125876 + Interview Questions in General QA

1.	\(\frac{1}{2}^{-2}÷\frac{1}{2}^{-2}\)A) (1/2)3 B) -1 C) 1 D) – 2
Answer» Correct option is (C) 1 \((\frac{1}{2})^{-2}\div(\frac{1}{2})^{-2}=(\frac{1}{2})^{-2}\times\left[(\frac{1}{2})^{-2}\right]^{-1}\) \(=(\frac{1}{2})^{-2}\times(\frac12)^2=(\frac{1}{2})^{-2+2}\) \(=(\frac12)^0=1\) Correct option is C) 1 The answer is c) 1 C) 1 2^2/2^2 = 1

1.

\(\frac{1}{2}^{-2}÷\frac{1}{2}^{-2}\)A) (1/2)3 B) -1 C) 1 D) – 2

Answer»

Correct option is (C) 1

\((\frac{1}{2})^{-2}\div(\frac{1}{2})^{-2}=(\frac{1}{2})^{-2}\times\left[(\frac{1}{2})^{-2}\right]^{-1}\) \(=(\frac{1}{2})^{-2}\times(\frac12)^2=(\frac{1}{2})^{-2+2}\) \(=(\frac12)^0=1\)

Correct option is C) 1

The answer is c) 1

C) 1

2^2/2^2

= 1

Discussion

2.	Frame five questions using the picture clues. Begin with “Have you ever”.1. Write a story2. Visit the Tajmahal3. Cook briyani4. Watch a horror film5. Play Ten pin bowling6. Go swimming
Answer» 1. Have you ever written a story? 2. Have you ever visited the Tajmahal? 3. Have you ever cooked biryani? 4. Have you ever watched a horror film? 5. Have you ever played Ten pin bowling ? 6. Have you ever gone for swimming?

2.

Frame five questions using the picture clues. Begin with “Have you ever”.1. Write a story2. Visit the Tajmahal3. Cook briyani4. Watch a horror film5. Play Ten pin bowling6. Go swimming

Answer»

1. Have you ever written a story?

2. Have you ever visited the Tajmahal?

3. Have you ever cooked biryani?

4. Have you ever watched a horror film?

5. Have you ever played Ten pin bowling ?

6. Have you ever gone for swimming?

Discussion

3.	Give an account on: i. Sacrum ii. Coccyx
Answer» i. Sacrum: 1. It is a triangular bone formed by the fusion of five sacral vertebrae. 2. It is located in pelvic cavity between two hip bones. 3. The anterior end of sacrum is broad and posterior end is narrow. 4. It consists of vertebral foramina formed by the fusion of vertebrae. 5. The reduced neural spines can be observed projecting from dorsal aspect of sacrum. 6. Function: It gives strength to pelvic girdle, ii. Coccyx: 1. It is a triangular bone which is formed by fusion of four coccygeal vertebrae. 2. It is reduced and does not show vertebral foramina and spinous processes. 3. The transverse processes of coccygeal vertebrae are reduced. The sacrum is a single bone comprised of five separate vertebrae that fuse during adulthood. It forms the foundation of the lower back and the pelvis. The sacrum is a concave sphenoid bone that sits at the bottom of the spinal column. The base is connected to the largest and lowest of the lumbar vertebrae, L5. The sacrum and coccyx are unlike other bones in your spinal column. The sacrum, sometimes called the sacral vertebra or sacral spine (S1), is a large, flat triangular shaped bone nested between the hip bones and positioned below the last lumbar vertebra (L5). The coccyx, commonly known as the tailbone, is below the sacrum. Individually, the sacrum and coccyx are composed of smaller bones that fuse (grow into a solid bone mass) together by age 30. The sacrum is made up of 5 fused vertebrae (S1-S5) and 3 to 5 small bones fuse creating the coccyx. Both structures are weight-bearing and integral to functions such as walking, standing and sitting. Sacrum and Lumbosacral Spine The sacrum is located in between the right and left iliac bones (hips) and forms the back of the pelvis. The sacrum, along with the coccyx and 2 sacroiliac joints make up the pelvic girdle. The top of the sacrum (S1) joins the last lumbar vertebra (L5) and together create the lumbosacral spine. Where S1 joins L5 helps form the lumbosacral curves: lumbar lordosis and lumbar kyphosis. Lordotic and kyphotic curvature works together to support the upper body, bear and distribute weight/forces, and helps maintain spinal balance and functional flexibility. Lordosis is the inward curve. Too much lordosis can cause swayback that is sometimes associated with spondylolisthesis. Loss of lordosis can cause spinal imbalance and may lead to flatback syndrome. The term kyphosis refers to a normal outward curve. The sacrum’s location—at the intersection of the spine and pelvis—means that it plays an especially important role to both your low back and hips. The sacrum’s joints are weight-bearing and help to stabilize this region of the spinal column. Like other spinal levels, ligaments, tendons and muscle help support and stabilize joint movement. Lumbosacral joint: This joint occurs at L5 and S1—it essentially connects the lumbar spine to the sacrum. There is a great amount of pressure at this meeting point, as the curve of your spine shifts at L5-S1 from lordotic (lumbar lordosis, forward curve) to kyphotic (sacral kyphosis, backward curve). The L5-S1 level is weight-bearing and absorbs and distributes the upper body’s weight at rest and movement. This is one reason why disc herniation and spondylolisthesis are more common at L5-S1. Sacroiliac (SI) joints: The SI joints connect the sacrum to the left and right sides of the pelvis. Unlike other joints in the body (eg, knees), the span of movement of either SI joint is minimal. These joints are essential to walking, standing, and hip stability. Sacroiliitis and SI joint dysfunction are two spinal disorders related to the sacroiliac joints. Other spinal disorders related to the sacral spine include sciatica, Tarlov cysts, and spinal chordoma—a common type of spinal bone cancer. Coccyx’s Role and Function The coccyx, or tailbone, is located just below the sacrum. Though it’s much smaller than the sacrum, it too has an important weight-bearing role. The coccyx helps support your weight while you sit. If you lean back while sitting, such as reclining in a chair, the pressure on your coccyx increases. An injury in this coccygeal region can cause tailbone pain, which is known as coccydynia. It is often characterized by inflammation of the coccyx’s connective tissue resulting in tailbone pain that worsens when sitting. Tailbone fracture that may occur from a traumatic event, such as a fall, can also cause this pain. Sacral and Coccygeal Nerves The spinal cord ends at L1-L2 creating the cauda equina; a bundle of spinal nerves resembling the tail of a horse. In the sacrum, are the sacral nerves; called the sacral plexus—the term “plexus” simply means a network of nerve structures. The sacral plus with the lumbar plexus create the lumbosacral plexus. The sciatic nerve is the largest nerve in the sacral plexus. Compression of the sciatica nerve causes a group of symptoms called sciatica that are notoriously known for lower back and leg pain. The coccygeal nerve is the one serving the tailbone (ie, coccyx). There are 5 sacral nerves (part of the spinal cord) numbered S1 through S5. The first sacral spinal nerve serves your groin area and hips; S2 the back of your thighs; S3 the middle of the buttock area; and S4 and S5 the anus and vagina. An injury or trauma to the sacral spine may cause stress fractures or more serious bone fracture. These fractures are painful and may cause sacral nerve compression. Symptoms may include lower back pain, leg pain, bowel or bladder dysfunction and/or unusual feelings in the buttock(s) or groin. Osteoporosis and/or spinal inflammatory arthritis may increase your risk for a sacral fracture.

3.

Give an account on: i. Sacrum ii. Coccyx

Answer»

i. Sacrum:

1. It is a triangular bone formed by the fusion of five sacral vertebrae.

2. It is located in pelvic cavity between two hip bones.

3. The anterior end of sacrum is broad and posterior end is narrow.

4. It consists of vertebral foramina formed by the fusion of vertebrae.

5. The reduced neural spines can be observed projecting from dorsal aspect of sacrum.

6. Function: It gives strength to pelvic girdle,

ii. Coccyx:

1. It is a triangular bone which is formed by fusion of four coccygeal vertebrae.

2. It is reduced and does not show vertebral foramina and spinous processes.

3. The transverse processes of coccygeal vertebrae are reduced.

The sacrum is a single bone comprised of five separate vertebrae that fuse during adulthood. It forms the foundation of the lower back and the pelvis. The sacrum is a concave sphenoid bone that sits at the bottom of the spinal column. The base is connected to the largest and lowest of the lumbar vertebrae, L5.

The sacrum and coccyx are unlike other bones in your spinal column. The sacrum, sometimes called the sacral vertebra or sacral spine (S1), is a large, flat triangular shaped bone nested between the hip bones and positioned below the last lumbar vertebra (L5). The coccyx, commonly known as the tailbone, is below the sacrum.

Individually, the sacrum and coccyx are composed of smaller bones that fuse (grow into a solid bone mass) together by age 30. The sacrum is made up of 5 fused vertebrae (S1-S5) and 3 to 5 small bones fuse creating the coccyx. Both structures are weight-bearing and integral to functions such as walking, standing and sitting.

Sacrum and Lumbosacral Spine

The sacrum is located in between the right and left iliac bones (hips) and forms the back of the pelvis. The sacrum, along with the coccyx and 2 sacroiliac joints make up the pelvic girdle. The top of the sacrum (S1) joins the last lumbar vertebra (L5) and together create the lumbosacral spine.

Where S1 joins L5 helps form the lumbosacral curves: lumbar lordosis and lumbar kyphosis. Lordotic and kyphotic curvature works together to support the upper body, bear and distribute weight/forces, and helps maintain spinal balance and functional flexibility.

Lordosis is the inward curve. Too much lordosis can cause swayback that is sometimes associated with spondylolisthesis.

Loss of lordosis can cause spinal imbalance and may lead to flatback syndrome.

The term kyphosis refers to a normal outward curve.

The sacrum’s location—at the intersection of the spine and pelvis—means that it plays an especially important role to both your low back and hips. The sacrum’s joints are weight-bearing and help to stabilize this region of the spinal column. Like other spinal levels, ligaments, tendons and muscle help support and stabilize joint movement.

Lumbosacral joint: This joint occurs at L5 and S1—it essentially connects the lumbar spine to the sacrum.

There is a great amount of pressure at this meeting point, as the curve of your spine shifts at L5-S1 from lordotic (lumbar lordosis, forward curve) to kyphotic (sacral kyphosis, backward curve). The L5-S1 level is weight-bearing and absorbs and distributes the upper body’s weight at rest and movement. This is one reason why disc herniation and spondylolisthesis are more common at L5-S1.

Sacroiliac (SI) joints: The SI joints connect the sacrum to the left and right sides of the pelvis. Unlike other joints in the body (eg, knees), the span of movement of either SI joint is minimal. These joints are essential to walking, standing, and hip stability. Sacroiliitis and SI joint dysfunction are two spinal disorders related to the sacroiliac joints.

Other spinal disorders related to the sacral spine include sciatica, Tarlov cysts, and spinal chordoma—a common type of spinal bone cancer.

Coccyx’s Role and Function

The coccyx, or tailbone, is located just below the sacrum. Though it’s much smaller than the sacrum, it too has an important weight-bearing role. The coccyx helps support your weight while you sit. If you lean back while sitting, such as reclining in a chair, the pressure on your coccyx increases.

An injury in this coccygeal region can cause tailbone pain, which is known as coccydynia. It is often characterized by inflammation of the coccyx’s connective tissue resulting in tailbone pain that worsens when sitting. Tailbone fracture that may occur from a traumatic event, such as a fall, can also cause this pain.

Sacral and Coccygeal Nerves

The spinal cord ends at L1-L2 creating the cauda equina; a bundle of spinal nerves resembling the tail of a horse. In the sacrum, are the sacral nerves; called the sacral plexus—the term “plexus” simply means a network of nerve structures. The sacral plus with the lumbar plexus create the lumbosacral plexus. The sciatic nerve is the largest nerve in the sacral plexus. Compression of the sciatica nerve causes a group of symptoms called sciatica that are notoriously known for lower back and leg pain. The coccygeal nerve is the one serving the tailbone (ie, coccyx).

There are 5 sacral nerves (part of the spinal cord) numbered S1 through S5. The first sacral spinal nerve serves your groin area and hips; S2 the back of your thighs; S3 the middle of the buttock area; and S4 and S5 the anus and vagina.

An injury or trauma to the sacral spine may cause stress fractures or more serious bone fracture. These fractures are painful and may cause sacral nerve compression. Symptoms may include lower back pain, leg pain, bowel or bladder dysfunction and/or unusual feelings in the buttock(s) or groin. Osteoporosis and/or spinal inflammatory arthritis may increase your risk for a sacral fracture.

Discussion

4.	New Market has employed Aryan Kumar to manage and maintain their networking architecture and wide area connectivity. Which type of job will best describe his job profile?
Answer» Networking Engineer will best describe his job profile.

Discussion

5.	Reena wants to get employment opportunities based on IT. What are the options for employments?
Answer» Web designing and developing, E-Learning, advertising etc are the options for employments opportunities based on IT.

Discussion

6.	Balance the following equations:(a) N2 + H2 → NH3(b) H2 + O2 → H2O(c) Na2O + H2O → NaOH(d) CO + O2 → CO2(e) Zn + HCl → ZnCl2 + H2
Answer» (a) N₂ + 3H₂ → 2NH₃ (b) 2H₂ + O₂ → 2H₂O (c) Na₂O + H₂O → 2NaOH (d) 2CO + O₂ → 2CO₂ (e) Zn + 2HCl → ZnCl₂ + H₂

6.

Balance the following equations:(a) N2 + H2 → NH3(b) H2 + O2 → H2O(c) Na2O + H2O → NaOH(d) CO + O2 → CO2(e) Zn + HCl → ZnCl2 + H2

Answer»

(a) N₂ + 3H₂ → 2NH₃

(b) 2H₂ + O₂ → 2H₂O

(c) Na₂O + H₂O → 2NaOH

(d) 2CO + O₂ → 2CO₂

(e) Zn + 2HCl → ZnCl₂ + H₂

Discussion

7.	Balance the following equations. Also name the products formed. The first one is done for you.1. NaNO3 → NaNO2 + O2 Name of product(s)2. K + Cl2 → KCl 3. Ag + S → Ag2S 4. Mg + O2 → MgO 5. KClO3 → KCl + O2
Answer» 1. 2NaNO₃ → 2NaNO₂ + O₂ Sodium nitrite, oxygen 2. 2K + Cl₂ → 2KCl Potassium chloride 3. 2Ag + S → Ag₂S Silver sulphide 4. 2Mg + O₂ → 2MgO Magnesium oxide 5. 2KClO₃ → 2KCl + 3O₂ Potassium chloride, oxygen

7.

Balance the following equations. Also name the products formed. The first one is done for you.1. NaNO3 → NaNO2 + O2 Name of product(s)2. K + Cl2 → KCl 3. Ag + S → Ag2S 4. Mg + O2 → MgO 5. KClO3 → KCl + O2

Answer»

1. 2NaNO₃ → 2NaNO₂ + O₂ Sodium nitrite, oxygen

2. 2K + Cl₂ → 2KCl Potassium chloride

3. 2Ag + S → Ag₂S Silver sulphide

4. 2Mg + O₂ → 2MgO Magnesium oxide

5. 2KClO₃ → 2KCl + 3O₂ Potassium chloride, oxygen

Discussion

8.	What information do you get from the equation H2+ Cl2 → 2HCl ?
Answer» (a)Hydrogen and chlorine molecules are the reactants. (b)They are in gaseous form. (c)The product is hydrogen chloride gas. (d)Two molecules of hydrogen chloride are formed

8.

What information do you get from the equation H2+ Cl2 → 2HCl ?

Answer»

(a)Hydrogen and chlorine molecules are the reactants.

(b)They are in gaseous form.

(c)The product is hydrogen chloride gas.

(d)Two molecules of hydrogen chloride are formed

Discussion

9.	State what you would observe when the following substances are heated in a glass test tube:(i) Red lead(ii) Copper (II) carbonate
Answer» (i) 2Pb₃O₄ → 6PbO + O₂ ↑ The dark red lead as red powder changes to yellow color. The yellow color residue on further heating sticks to the tube and give a reddish color to glass. A colorless and odorless gas is evolved. (ii) CuCO₃ → CuO + CO₂ ↑ The blue-green powder turns black and a colorless gas is evolved which extinguishes a burning flame.

9.

State what you would observe when the following substances are heated in a glass test tube:(i) Red lead(ii) Copper (II) carbonate

Answer»

(i) 2Pb₃O₄ → 6PbO + O₂ ↑

The dark red lead as red powder changes to yellow color. The yellow color residue on further heating sticks to the tube and give a reddish color to glass. A colorless and odorless gas is evolved.

(ii) CuCO₃ → CuO + CO₂ ↑

The blue-green powder turns black and a colorless gas is evolved which extinguishes a burning flame.

Discussion

10.	Balance the following chemical equations : (a) FeS + HCl → FeCl2 + H2S (b) Na2CO3 + HCl → NaCI + H2O + CO2(c) H2 + O2 → H2O (d) Na2O + H2O → NaOH
Answer» (a) FeS + 2HCl → FeCl₂ + H₂S (b) Na₂CO₃ + 2HCl → 2NaCI + H₂O + CO₂ (c) 2H₂ + O₂ → 2H₂O (d) Na₂O + H₂O → 2NaOH

10.

Balance the following chemical equations : (a) FeS + HCl → FeCl2 + H2S (b) Na2CO3 + HCl → NaCI + H2O + CO2(c) H2 + O2 → H2O (d) Na2O + H2O → NaOH

Answer»

(a) FeS + 2HCl → FeCl₂ + H₂S

(b) Na₂CO₃ + 2HCl → 2NaCI + H₂O + CO₂

(c) 2H₂ + O₂ → 2H₂O

(d) Na₂O + H₂O → 2NaOH

Discussion

11.	Fill in the blanks: (a) The substances which undergo chemical change are called................(b) The substances formed as a result of a chemical reaction are called..................(c) During a chemical reaction transfer of................ takes place. (d) The basic conditions necessary for a chemical reaction is..................(e) In some chemical reactions an insoluble................ is formed when two solutions are mixed.
Answer» (a) The substances which undergo chemical change are called reactants. (b) The substances formed as a result of a chemical reaction are called products. (c) During a chemical reaction transfer of energy takes place. (d) The basic conditions necessary for a chemical reaction is close contact. (e) In some chemical reactions, an insoluble precipitate is formed when two solutions are mixed.

11.

Fill in the blanks: (a) The substances which undergo chemical change are called................(b) The substances formed as a result of a chemical reaction are called..................(c) During a chemical reaction transfer of................ takes place. (d) The basic conditions necessary for a chemical reaction is..................(e) In some chemical reactions an insoluble................ is formed when two solutions are mixed.

Answer»

(a) The substances which undergo chemical change are called reactants.

(b) The substances formed as a result of a chemical reaction are called products.

(c) During a chemical reaction transfer of energy takes place.

(d) The basic conditions necessary for a chemical reaction is close contact.

(e) In some chemical reactions, an insoluble precipitate is formed when two solutions are mixed.

Discussion

12.	Write the molecular formula for the oxide and sulphide of following elements.(a) Sodium (b) Calcium (c) Hydrogen
Answer» (a) Sodium oxide Na₂O Sodium sulphide Na₂S (b) Calcium oxide CaO Calcium sulphide CaS (c) Hydrogen oxide H₂O Hydrogen sulphide H₂S

12.

Write the molecular formula for the oxide and sulphide of following elements.(a) Sodium (b) Calcium (c) Hydrogen

Answer»

(a) Sodium oxide Na₂O

Sodium sulphide Na₂S

(b) Calcium oxide CaO

Calcium sulphide CaS

(c) Hydrogen oxide H₂O

Hydrogen sulphide H₂S

Discussion

13.	Explain the following reaction with one suitable example for each.(a) Combination reactions(b) Decomposition reaction(c) Displacement reaction(d) Double decomposition reaction
Answer» (a) Combination reactions: In this reaction, two or more substances combine to form a new substance, e.g. Burning of hydrogen in air. (b) Decomposition reaction: In this reaction, a substance breaks upon heating to form two or simpler substances, e.g. Electrolysis of water. (c) Displacement reaction: In this reaction a more reactive element displaces a less reactive element from its compound, e.g. Reaction of iron with copper sulphate. (d) Double decomposition reaction: In this reaction, two compounds in solution state react with each other to form two new substances by exchanging their radicals, e.g. Reaction of sodium hydroxide with dilute hydrochloric acid.

13.

Explain the following reaction with one suitable example for each.(a) Combination reactions(b) Decomposition reaction(c) Displacement reaction(d) Double decomposition reaction

Answer»

(a) Combination reactions: In this reaction, two or more substances combine to form a new substance, e.g. Burning of hydrogen in air.

(b) Decomposition reaction: In this reaction, a substance breaks upon heating to form two or simpler substances, e.g. Electrolysis of water.

(c) Displacement reaction: In this reaction a more reactive element displaces a less reactive element from its compound, e.g. Reaction of iron with copper sulphate.

(d) Double decomposition reaction: In this reaction, two compounds in solution state react with each other to form two new substances by exchanging their radicals, e.g. Reaction of sodium hydroxide with dilute hydrochloric acid.

Discussion

14.	Write your observations and name the products when(a) Zinc reacts with dilute hydrochloric acid.(b) Iron nails are added to an aqueous solution of copper sulphate.(c) An aqueous solution of barium chloride is added to dilute sulphuric acid.
Answer» (a) When zinc pieces are added to hydrochloric acid, zinc displaces hydrogen. As a result, zinc chloride and hydrogen gas are produced. (b) When iron pieces are added to an aqueous solution of copper sulphate iron being more reactive displaces copper from copper sulphate solution to produce ferrous sulphate. (c) An aqueous solution of barium chloride, when mixed with dilute sulphuric acid, produces a white insoluble solid barium sulphate and hydrochloric acid.

14.

Write your observations and name the products when(a) Zinc reacts with dilute hydrochloric acid.(b) Iron nails are added to an aqueous solution of copper sulphate.(c) An aqueous solution of barium chloride is added to dilute sulphuric acid.

Answer»

(a) When zinc pieces are added to hydrochloric acid, zinc displaces hydrogen. As a result, zinc chloride and hydrogen gas are produced.

(b) When iron pieces are added to an aqueous solution of copper sulphate iron being more reactive displaces copper from copper sulphate solution to produce ferrous sulphate.

(c) An aqueous solution of barium chloride, when mixed with dilute sulphuric acid, produces a white insoluble solid barium sulphate and hydrochloric acid.

Discussion

15.	Differentiate between:(a) Reactants and products(b) A balanced and an unbalanced chemical equation
Answer» (a) Reactants and products Reactants 1. The substances that react with one another are called reactants. 2. Reactants are written on the left-hand side of the equation. Products 1. The new substances formed are called products. 2. Products are written on the right-hand side of equation. (b) A balanced and an unbalanced chemical equation Balanced chemical 1. A balanced chemical reaction is the one in which the number of atoms of each element on the reactant side is equal to the number of atoms of that element on the product side. 2. Ex- H₂ + Cl₂ → HCl Unbalanced chemical 1. Number of elements on reactant side is not equal to the number of elements on the product side. 2. Ex- H₂ + Cl₂ → 2HCl

15.

Differentiate between:(a) Reactants and products(b) A balanced and an unbalanced chemical equation

Answer»

(a) Reactants and products

Reactants

1. The substances that react with one another are called reactants.

2. Reactants are written on the left-hand side of the equation.

Products

1. The new substances formed are called products.

2. Products are written on the right-hand side of equation.

(b) A balanced and an unbalanced chemical equation

Balanced chemical

1. A balanced chemical reaction is the one in which the number of atoms of each element on the reactant side is equal to the number of atoms of that element on the product side.

2. Ex- H₂ + Cl₂ → HCl

Unbalanced chemical

1. Number of elements on reactant side is not equal to the number of elements on the product side.

2. Ex- H₂ + Cl₂ → 2HCl

Discussion

16.	(a) Define chemical reaction. (b) What is a chemical equation? (c) Why do we need to balance chemical equations?
Answer» (a) Chemical reaction: Any chemical change in a matter which involves its transformation into one or more new substances is called a chemical reaction. (b) Chemical equation: A chemical equation is the symbolic representation of a chemical reaction using the symbols and the formula of the substances involved in the reaction. (c) A chemical equation needs to be balanced so as to make the number of the atoms of the reactants equal to the number of the atoms of the products.

16.

(a) Define chemical reaction. (b) What is a chemical equation? (c) Why do we need to balance chemical equations?

Answer»

(a) Chemical reaction: Any chemical change in a matter which involves its transformation into one or more new substances is called a chemical reaction.

(b) Chemical equation: A chemical equation is the symbolic representation of a chemical reaction using the symbols and the formula of the substances involved in the reaction.

(c) A chemical equation needs to be balanced so as to make the number of the atoms of the reactants equal to the number of the atoms of the products.

Discussion

17.	Complete the following : XeF4 + H2O → ……………… + HF
Answer» XeF₄ + H₂O → XeOF₂ + 2HF

Discussion

18.	State four conditions necessary for chemical reactions to take place.
Answer» Conditions necessary for chemical reactions : 1. Close contact 2. Solution form 3. Heat 4. Light 5. Catalyst

18.

State four conditions necessary for chemical reactions to take place.

Answer»

Conditions necessary for chemical reactions :

1. Close contact

2. Solution form

3. Heat

4. Light

5. Catalyst

Discussion

19.	XeF4 on partial hydrolysis produces : (a) XeF2 (b) XeOF2 (c) XeOF4 (d) XeO3
Answer» Option : (c) XeOF₄

Discussion

20.	Write ‘true’ or ‘false’ for the following statements : (a) No new substance is formed during a chemical reaction(b) Hydrogen sulphide has rotten egg smell : (c) When potassium iodide solution is added to lead acetate solution a red precipitate is formed (d) A black residue is formed when sugar is heated(e) When iron and sulphur are heated together a grey mass is formed which is attracted by a magnet (f) A chemical equation gives only qualitative information of a chemical reaction
Answer» (a) True (b) True (c) False (d) True (e) False (f) False

20.

Write ‘true’ or ‘false’ for the following statements : (a) No new substance is formed during a chemical reaction(b) Hydrogen sulphide has rotten egg smell : (c) When potassium iodide solution is added to lead acetate solution a red precipitate is formed (d) A black residue is formed when sugar is heated(e) When iron and sulphur are heated together a grey mass is formed which is attracted by a magnet (f) A chemical equation gives only qualitative information of a chemical reaction

Answer»

(a) True

(b) True

(c) False

(d) True

(e) False

(f) False

Discussion

21.	(a) Define chemical reaction.(b) What is a chemical equation?(c) Why do we need to balance chemical equations?
Answer» (a) Chemical reaction: Any chemical change in matter which involves its transformation into one or more new substances is called a chemical reaction. (b) Chemical equation: A chemical equation is the symbolic representation of a chemical reaction using the symbols and the formula of the substances involved in the reaction. (c) A chemical equation needs to be balanced so as to make the number of the atoms of the reactants equal to the number of the atoms of the products.

21.

(a) Define chemical reaction.(b) What is a chemical equation?(c) Why do we need to balance chemical equations?

Answer»

(a) Chemical reaction: Any chemical change in matter which involves its transformation into one or more new substances is called a chemical reaction.

(b) Chemical equation: A chemical equation is the symbolic representation of a chemical reaction using the symbols and the formula of the substances involved in the reaction.

(c) A chemical equation needs to be balanced so as to make the number of the atoms of the reactants equal to the number of the atoms of the products.

Discussion

22.	Define:(a) Radical(b) Valency(c) Molecular formula
Answer» (a) Radical: A radical is an atom of an element or a group of atoms of different elements that behaves as a single unit with a positive or negative charge on it. (b) Valency: It is the number of electrons donated or accepted by the valence shell of an atom during chemical combination. (c) Molecular formula: It is a symbolic representation of a molecule. It shows the number of atoms of each element present in it. These atoms combine in the whole number to form the molecule.

22.

Define:(a) Radical(b) Valency(c) Molecular formula

Answer»

(a) Radical: A radical is an atom of an element or a group of atoms of different elements that behaves as a single unit with a positive or negative charge on it.

(b) Valency: It is the number of electrons donated or accepted by the valence shell of an atom during chemical combination.

(c) Molecular formula: It is a symbolic representation of a molecule. It shows the number of atoms of each element present in it. These atoms combine in the whole number to form the molecule.

Discussion

23.	What are the ways by which a chemical equation can be made more informative ?
Answer» A chemical equation can give more informations in the following ways: 1. The physical state of the reactants and products can be indicated by putting (s) for solid, (l) for liquid, (g) for gas and (aq) for aqueous state. 2. Evolution or absorption of heat during the reaction can be denoted by adding or subtracting a heated term on the product side. 3. Temperature, pressure and catalyst can be indicated above the arrow (→ or =) separating the reactants and products. 4. The concentration of reactants and products are indicated by adding word (dil) for dilute and (cone) for concentrated before their formula. 5. By the sign, → or ⇌ information about irreversible and reversible reactions can be obtained.

23.

What are the ways by which a chemical equation can be made more informative ?

Answer»

A chemical equation can give more informations in the following ways:

1. The physical state of the reactants and products can be indicated by putting (s) for solid, (l) for liquid, (g) for gas and (aq) for aqueous state.

2. Evolution or absorption of heat during the reaction can be denoted by adding or subtracting a heated term on the product side.

3. Temperature, pressure and catalyst can be indicated above the arrow (→ or =)

separating the reactants and products.

4. The concentration of reactants and products are indicated by adding word (dil) for dilute and (cone) for concentrated before their formula.

5. By the sign, → or ⇌ information about irreversible and reversible reactions can be obtained.

Discussion

24.

What is variable valency ? Give two examples of elements showing variable valency.

Answer»

Certain elements exhibit more than one valency, that means they show variable valency.

Ferrous is written as Iron (II) and Ferric is written as Iron (III).

Metal	Radicals	Radicals Valency
Iron	Ferrous [Iron (II)] Ferric [Iron (III)]	2 3
Copper	Cuprous [Copper (I)] Cupric [Copper (II)]	1 2

Discussion

25.	Write the molecular formula for the following compounds and name the elements present.(a) Baking soda (b) Common salt(c) Sulphuric acid (d) Nitric acid
Answer» (a) Baking soda — NaHCO₃ Elements present in Baking soda are sodium, hydrogen, oxygen, and carbon. (b) Common salt — NaCl Element present are: Sodium and chlorine. (c) Sulphuric acid — H₂SO₄ Element present are: Hydrogen, sulphur and oxygen. (d) Nitric acid — HNO₃ Elements present are: Hydrogen, nitrogen and oxygen.

25.

Write the molecular formula for the following compounds and name the elements present.(a) Baking soda (b) Common salt(c) Sulphuric acid (d) Nitric acid

Answer»

(a) Baking soda — NaHCO₃

Elements present in Baking soda are sodium, hydrogen, oxygen, and carbon.

(b) Common salt — NaCl

Element present are: Sodium and chlorine.

(c) Sulphuric acid — H₂SO₄

Element present are: Hydrogen, sulphur and oxygen.

(d) Nitric acid — HNO₃

Elements present are: Hydrogen, nitrogen and oxygen.

Discussion

26.	The valency of aluminium is 3. Write the valency of other radicals present in the following compounds.(a) Aluminium chloride(b) Aluminium oxide(c) Aluminium nitride(d) Aluminium sulphate
Answer» (a) Aluminium chloride — (AlCl₃) here valency of Al is 3. Other radical – Chloride (Cl^-) Valency of chloride = 1 (b) Aluminium oxide — (Al₂O₃) Here valency of Al is 3 Other radical presents = oxide (O^2-) Valency of O^2- = 2 (c) Aluminium nitride — (Al N) Here valency of aluminium = 3 Another radical = Nitride (N^3-) Valency of nitride (N^3-) = 3 (d) Aluminium sulphate — Al₂(SO₄)³ Here valency of aluminium is 3 Another radical = Sulphate (SO ₄^2-) Valency of (SO₄^2-) = 2

26.

The valency of aluminium is 3. Write the valency of other radicals present in the following compounds.(a) Aluminium chloride(b) Aluminium oxide(c) Aluminium nitride(d) Aluminium sulphate

Answer»

(a) Aluminium chloride — (AlCl₃) here valency of Al is 3.

Other radical – Chloride (Cl^-)

Valency of chloride = 1

(b) Aluminium oxide — (Al₂O₃)

Here valency of Al is 3

Other radical presents = oxide (O^2-)

Valency of O^2- = 2

(c) Aluminium nitride — (Al N)

Here valency of aluminium = 3

Another radical = Nitride (N^3-)

Valency of nitride (N^3-) = 3

(d) Aluminium sulphate — Al₂(SO₄)³

Here valency of aluminium is 3

Another radical = Sulphate (SO ₄^2-)

Valency of (SO₄^2-) = 2

Discussion

27.	What are Saturn’s rings made of ?
Answer» Saturn’s rings are made of dust and ice.

Discussion

28.	How much time do the Sun’s rays take to travel from the space to the earth?
Answer» 8 minutes 20 seconds

Discussion

29.	How much time do the Sun’s rays take to travel from the space to the earth?
Answer» 8 minutes 20 seconds

Discussion

30.	Why is melting point of LiCl lower than NaCl?
Answer» LiCl has lower melting point than NaCl because it is covalent whereas NaCl is ionic.

Discussion

31.	Give the order in which the melting points of halides of sodium decrease and why?
Answer» NaF > NaCl > NaBr > Nal. Greater the difference in electronegativity more will be ionic character, higher will be melting point due to high lattice energy.

Discussion

32.	Explain Sorption.
Answer» Sorption:- When adsorption and absorption takes place simultaneously, it is called sorption.

32.

Explain Sorption.

Answer»

Sorption:-

When adsorption and absorption takes place simultaneously, it is called sorption.

Discussion

33.	The matrix A = \(\begin{pmatrix}2&-2&-4 \\- 1 &3&4\\1&-2&-3\end{pmatrix}\) isA. Nonsingular B. Idempotent C. Nilpotent D. Orthogonal
Answer» Here the diagonal value is 2 + 3 - 3 = 1 So the given matrix is idempotent.

33.

The matrix A = \(\begin{pmatrix}2&-2&-4 \\- 1 &3&4\\1&-2&-3\end{pmatrix}\) isA. Nonsingular B. Idempotent C. Nilpotent D. Orthogonal

Answer»

Here the diagonal value is 2 + 3 - 3 = 1

So the given matrix is idempotent.

Discussion

34.	Write the IUPAC names [Cr(NH3)4Cl2]+
Answer» Tetraamminedichloro chromium (III) ion.

Discussion

35.	Describe the principle of preparation of SO2 gas in the laboratory. Discuss the following properties of SO2- (a) Acidic properties (b) Bleaching properties (c) Oxidising properties and (d) Reducing properties.
Answer» Preparation of SO₂ gas in the laboratory:- Principle:- SO₂ gas is prepared in the laboratory by the action of Cu and conc. H₂SO₄ Cu + 2H₂SO₄→ CuSO₄ + 2H₂O + CO₂ SO₂ gas is collected in the gas jar by the displacement of air. Following reaction of SO₂ gas: (a) Acidic properties: It is an acidic oxide. It react with water and forms sulphurous acid. SO₂ + H₂O → H₂SO₃ (b) Bleaching properties: It bleaches the colour of moist substances. Its bleaching properties is due to reduction. It combines with water and form sulphuric acid and nascent hydrogen which bleaches the coloured substance into colourless: SO₂ + 2H₂O → H₂SO₄ + 2[H] Colour + 2[H] → colourless (c) Oxidising properties: It act as an oxidising agent is some reactions. e.g.- (i) It oxidises H₂S into sulphur SO₂ + 2H₂S → 3S + 2H₂O (ii) It oxidises iron powder into their oxide and sulphide. SO₂ + 3Fe → 2FeO + FeS (iii) It oxidises SnCl₂ in SnCl₄ SO₂ + 2SnCl₂ + 4HCl → S + 2SnCl₄ + 2H₂O (d) Reducing properties: Aqueous solution of SO₂ is a strong reducing agent. When SO₂ reacts with water produce nacesent hydrogen, which acts as strong reducing agent. 2H₂O + SO₂ → H₂SO₄ + 2[H] (i) It reduces halogens (Cl₂, Br₂ and I₂) in their halogen acids e.g. SO₂+ Cl₂ + 2H₂O → 2HCl + H₂SO₄ SO₂ + Br₂ + 2H₂O → 2HBr + H₂SO₄ SO₂ + I₂ + 2H₂O → 2HI + H₂SO₄ (ii) It reduces acidic solution of potassium permanganate into manganese sulphate. 2KMnO₄ + 5SO₂ + 2H₂O → 2MnSO₄ + K₂SO₄ + 2H₂SO₄

35.

Describe the principle of preparation of SO2 gas in the laboratory. Discuss the following properties of SO2- (a) Acidic properties (b) Bleaching properties (c) Oxidising properties and (d) Reducing properties.

Answer»

Preparation of SO₂ gas in the laboratory:-

Principle:- SO₂ gas is prepared in the laboratory by the action of Cu and conc. H₂SO₄

Cu + 2H₂SO₄→ CuSO₄ + 2H₂O + CO₂

SO₂ gas is collected in the gas jar by the displacement of air.

Following reaction of SO₂ gas:

(a) Acidic properties: It is an acidic oxide. It react with water and forms sulphurous acid.

SO₂ + H₂O → H₂SO₃

(b) Bleaching properties: It bleaches the colour of moist substances. Its bleaching properties is due to reduction. It combines with water and form sulphuric acid and nascent hydrogen which bleaches the coloured substance into colourless:

SO₂ + 2H₂O → H₂SO₄ + 2[H]

Colour + 2[H] → colourless

(c) Oxidising properties: It act as an oxidising agent is some reactions. e.g.-

(i) It oxidises H₂S into sulphur

SO₂ + 2H₂S → 3S + 2H₂O

(ii) It oxidises iron powder into their oxide and sulphide.

SO₂ + 3Fe → 2FeO + FeS

(iii) It oxidises SnCl₂ in SnCl₄

SO₂ + 2SnCl₂ + 4HCl → S + 2SnCl₄ + 2H₂O

(d) Reducing properties: Aqueous solution of SO₂ is a strong reducing agent. When SO₂ reacts with water produce nacesent hydrogen, which acts as strong reducing agent.

2H₂O + SO₂ → H₂SO₄ + 2[H]

(i) It reduces halogens (Cl₂, Br₂ and I₂) in their halogen acids e.g.

SO₂+ Cl₂ + 2H₂O → 2HCl + H₂SO₄

SO₂ + Br₂ + 2H₂O → 2HBr + H₂SO₄

SO₂ + I₂ + 2H₂O → 2HI + H₂SO₄

(ii) It reduces acidic solution of potassium permanganate into manganese sulphate.

2KMnO₄ + 5SO₂ + 2H₂O → 2MnSO₄ + K₂SO₄ + 2H₂SO₄

Discussion

36.	Find the sum without operation 1 + 3 + 5(A) 9(B) 8(C) 7(D) 6
Answer» The correct option is (A) 9.

Discussion

37.	What are the factors on which the rate of reaction depends? Discuss each factor in brief.
Answer» The rate of reaction depends upon the following factors:- (i) Concentration of the reactants:- Greater the concentration faster is the reaction. (ii) Presence of catalyst:- It increase the speed of the reaction by lowering the activation energy. (iii) Temperature:- The rate of reaction increases with increase of temp. in most of the case, the rate of reaction become almost double for every 10°C rise in temp. This is because of the increase in the number of effective collision with rise in temp. (iv) Surface area:- With increase in surface area rate of reaction increases. (v) Nature of reactants:- With change in reactants rate of reaction changes.

37.

What are the factors on which the rate of reaction depends? Discuss each factor in brief.

Answer»

The rate of reaction depends upon the following factors:-

(i) Concentration of the reactants:- Greater the concentration faster is the reaction.

(ii) Presence of catalyst:- It increase the speed of the reaction by lowering the activation energy.

(iii) Temperature:- The rate of reaction increases with increase of temp. in most of the case, the rate of reaction become almost double for every 10°C rise in temp. This is because of the increase in the number of effective collision with rise in temp.

(iv) Surface area:- With increase in surface area rate of reaction increases.

(v) Nature of reactants:- With change in reactants rate of reaction changes.

Discussion

38.	What is meant by zero order reaction? Give examples.
Answer» Zero Order Reaction:- Chemical reactions in which the rate of the reaction does not depend upon the concentration of any of the reactant, is a zero order reaction. In such a case the reaction proceeds at a constant rate. Thus for zero order reaction rate = k = constant. Examples:- (i) Decomposition of NH₃ on the surface for platinum. (ii) Decomposition of HI on Gold surface.

38.

What is meant by zero order reaction? Give examples.

Answer»

Zero Order Reaction:- Chemical reactions in which the rate of the reaction does not depend upon the concentration of any of the reactant, is a zero order reaction. In such a case the reaction proceeds at a constant rate. Thus for zero order reaction rate = k = constant.

Examples:- (i) Decomposition of NH₃ on the surface for platinum.

(ii) Decomposition of HI on Gold surface.

Discussion

39.

Find the smallest square number that is divisible by each of the numbers 8, 15, and 20.

Answer»

The number that is perfectly divisible by each of the numbers 8, 15, and 20 is their LCM.

2	8, 15, 20
2	4, 15, 10
2	2, 15, 5
3	1, 15, 5
5	1, 5, 5
	1, 1, 1

LCM of 8, 15, and 20 = 2 × 2 × 2 × 3 × 5 =120

Here, prime factors 2, 3, and 5 do not have their respective pairs. Therefore, 120 is not a perfect square.

Therefore, 120 should be multiplied by 2 × 3 × 5, i.e. 30, to obtain a perfect square.

Hence, the required square number is 120 × 2 × 3 × 5 = 3600

Discussion

40.

Find the smallest square number that is divisible by each of the numbers 4, 9, and 10.

Answer»

The number that will be perfectly divisible by each one of 4, 9, and 10 is their LCM. The LCM of these numbers is as follows.

2	4, 9, 10
2	2, 9, 5
3	1, 9, 5
3	1, 3, 5
5	1, 1, 5
	1, 1, 1

LCM of 4, 9, 10 = 2 × 2 × 3 × 3 × 5 =180

Here, prime factor 5 does not have its pair. Therefore, 180 is not a perfect square. If we multiply 180 with 5, then the number will become a perfect square. Therefore, 180 should be multiplied with 5 to obtain a perfect square.

Hence, the required square number is 180 × 5 = 900

Discussion

41.	What is manifestation?
Answer» The appearance of the symptoms of a disease is called manifestation of the disease.

Discussion

42.	Using factor theorem, factorize each of the following polynomial:y3 - 2y2 - 29y - 42
Answer» Let, f (y) = y³ - 2y² - 29y - 42 The factors of the constant term – 42 are \(\pm\) 1, \(\pm\) 2, \(\pm\) 3, \(\pm\) 6, \(\pm\) 7, \(\pm\) 14, \(\pm\) 21 and \(\pm\) 42 Putting y = - 2, we have f (-2) = (-2)³ – 2 (-2)² – 29 (-2) - 42 = - 8 – 8 + 58 - 42 = 0 So, (y + 2) is a factor of f (y) Let us now divide f (y) = y³ - 2y² - 29y - 42 by (y + 2) to get the other factors of f (x) Using long division method, we get y³ - 2y²- 29y - 42 = (y + 2) (y² – 4y – 21) y² – 4y - 21 = y² – 7y + 3y - 21 = y (y – 7) + 3 (y – 7) = (y – 7) (y + 3) Hence, y³ - 2y² - 29y - 42 = (y + 2) (y - 7) (y + 3)

42.

Using factor theorem, factorize each of the following polynomial:y3 - 2y2 - 29y - 42

Answer»

Let, f (y) = y³ - 2y² - 29y - 42

The factors of the constant term – 42 are \(\pm\) 1, \(\pm\) 2, \(\pm\) 3, \(\pm\) 6, \(\pm\) 7, \(\pm\) 14, \(\pm\) 21 and \(\pm\) 42

Putting y = - 2, we have

f (-2) = (-2)³ – 2 (-2)² – 29 (-2) - 42

= - 8 – 8 + 58 - 42

= 0

So,

(y + 2) is a factor of f (y)

Let us now divide

f (y) = y³ - 2y² - 29y - 42 by (y + 2) to get the other factors of f (x)

Using long division method, we get

y³ - 2y²- 29y - 42 = (y + 2) (y² – 4y – 21)

y² – 4y - 21 = y² – 7y + 3y - 21

= y (y – 7) + 3 (y – 7)

= (y – 7) (y + 3)

Hence,

y³ - 2y² - 29y - 42 = (y + 2) (y - 7) (y + 3)

Discussion

43.	What is immunization?
Answer» The creation of immunity usually against a particular disease, especially treatment by vaccination of an organism for the purpose of making it immune to a particular disease.

Discussion

44.	What is tissue culture? What are the different types of tissue culture? Describe briefly.
Answer» The production of new plants from a small piece of plant tissue (or cells) removed from the growing tips of a plant in a suitable growth medium is called tissue culture. The different types of tissue culture is as follows: 1. Seed Culture: Seeds may be cultured in vitro to generate seedlings or plants. It is the best method for raising the sterile seedling. The seed culture is done to get the different kinds of explants from aseptically grown plants which help in better maintenance of aseptic tissue. 2. Embryo Culture: Embryo culture is the sterile isolation and growth of an immature or mature embryo in vitro with the goal of obtaining a viable plant. In some plants seed dormancy may be due to chemical inhibitors or mechanical resistance, structures covering the embryo. Excision of embryos and culturing them in nutrient media help in developing viable seedlings. 3. Bud Culture: Buds contain quiescent or active meristems in the leaf axils, which are capable of growing into a shoot. Single node culture, where each node of the stem is cut and allowed to grow on a nutrient media to develop the shoot tip from the axil which ultimately develops into new plantlet. In axillary bud method, where the axillary buds are isolated from the leaf axils and develop into shoot tip under little high cytokinin concentration. 4. Callus Culture: Callus is basically more or less un-organised dedifferentiated mass of cells arising from any kind of explant under in vitro cultural conditions. The cells in callus are parenchymatous in nature, but may or may not be homogenous mass of cells. They are meristematic tissue, under special circumstances they may be again organised into shoot primordia or may develop into somatic embryos. The callus tissue from different plant species may be different in structure and growth habit. The callus growth is also dependent on factors like the type of explant and the growth conditions. After callus induction it can be sub-cultured regularly with appropriate new medium for growth and maintenance.

44.

What is tissue culture? What are the different types of tissue culture? Describe briefly.

Answer»

The production of new plants from a small piece of plant tissue (or cells) removed from the growing tips of a plant in a suitable growth medium is called tissue culture.

The different types of tissue culture is as follows:

1. Seed Culture: Seeds may be cultured in vitro to generate seedlings or plants. It is the best method for raising the sterile seedling. The seed culture is done to get the different kinds of explants from aseptically grown plants which help in better maintenance of aseptic tissue.

2. Embryo Culture: Embryo culture is the sterile isolation and growth of an immature or mature embryo in vitro with the goal of obtaining a viable plant. In some plants seed dormancy may be due to chemical inhibitors or mechanical resistance, structures covering the embryo. Excision of embryos and culturing them in nutrient media help in developing viable seedlings.

3. Bud Culture: Buds contain quiescent or active meristems in the leaf axils, which are capable of growing into a shoot. Single node culture, where each node of the stem is cut and allowed to grow on a nutrient media to develop the shoot tip from the axil which ultimately develops into new plantlet. In axillary bud method, where the axillary buds are isolated from the leaf axils and develop into shoot tip under little high cytokinin concentration.

4. Callus Culture: Callus is basically more or less un-organised dedifferentiated mass of cells arising from any kind of explant under in vitro cultural conditions. The cells in callus are parenchymatous in nature, but may or may not be homogenous mass of cells. They are meristematic tissue, under special circumstances they may be again organised into shoot primordia or may develop into somatic embryos.

The callus tissue from different plant species may be different in structure and growth habit. The callus growth is also dependent on factors like the type of explant and the growth conditions. After callus induction it can be sub-cultured regularly with appropriate new medium for growth and maintenance.

Discussion

45.	What do you understand by vaccination and immunization?
Answer» Vaccination: Vaccination means getting a dose of a vaccine against a particular disease. The vaccine could be in the form of an injection or even administered orally. Immunization: Immunization is a term that refers to the process of getting vaccinated. It helps in the prevention of diseases as the body gets immune to the disease after getting vaccinated. To eradicate a disease completely, the whole population of the place has to be immunized.

45.

What do you understand by vaccination and immunization?

Answer»

Vaccination: Vaccination means getting a dose of a vaccine against a particular disease. The vaccine could be in the form of an injection or even administered orally.

Immunization: Immunization is a term that refers to the process of getting vaccinated. It helps in the prevention of diseases as the body gets immune to the disease after getting vaccinated. To eradicate a disease completely, the whole population of the place has to be immunized.

Discussion

46.	Complete the statements using the proper option from those given below. Explain the statements. (mycotoxins, budding, rhizobium)a. Yeast reproduces asexually by the …………… method.b. Toxins of fungal origin are called …………….c. Leguminous plants can produce more proteins due to …………… .
Answer» a. The yeast cells develop small round bodies on the parent cell. These are called buds. New daughter cells develop from these buds. b. Mycotoxins are poisonous chemicals released into the food by fungi. This makes the food poisonous. c. (i) Nitrogenous compounds are required to produce proteins. (ii) Rhizobia produce nitrogenous compounds by fixing atmospheric nitrogen and make it available for their host plants like leguminous plants.

46.

Complete the statements using the proper option from those given below. Explain the statements. (mycotoxins, budding, rhizobium)a. Yeast reproduces asexually by the …………… method.b. Toxins of fungal origin are called …………….c. Leguminous plants can produce more proteins due to …………… .

Answer»

a. The yeast cells develop small round bodies on the parent cell. These are called buds. New daughter cells develop from these buds.

b. Mycotoxins are poisonous chemicals released into the food by fungi. This makes the food poisonous.

c. (i) Nitrogenous compounds are required to produce proteins.

(ii) Rhizobia produce nitrogenous compounds by fixing atmospheric nitrogen and make it available for their host plants like leguminous plants.

Discussion

47.	Flowers of Vallisneria spp are (A) Anaemophilous (B) Entomophilous (C) Hydrophilous. (D) Zoophilous
Answer» Correct Answer is: (C) Hydrophilous. • When pollination is affected with the help of water, it is called hydrophily. • The flowers pollinated by water current are known as hydrophilous. • Typical hydrophilous flowers are found in many submerged aquatic monocotyledonous plants like species of Vallisneria, Hydrilla, Najas, Zostera, etc

Discussion

48.	Mention two methods of treatment of the disease.
Answer» Surgery, radiotherapy, Chemotherapy

Discussion

49.

Describe the different methods for treatment of cancer.

Answer»

Cancer treatment

• The common approaches for treatment of cancer are:

a. Surgery: The tumour cells are removed with the help of surgery to check the spread of cancerous cells.

b. Radiation therapy: A lethal irradiation of tumour cell is done, taking proper care of the normal tissues surrounding the tumour mass.

c. Chemotherapy: Cancerous cells are killed by several chemotherapeutic drugs. These drugs exhibit side effects like hair loss, anaemia.

d. Immunotherapy: In this method, biological modifiers like α-interferons are used which activate the immune system and help in destroying the tumour.

Discussion

50.

In your locality, if a person is addicted to alcohol, what kind of behavioural changes do you observe in that person? Suggest measures to overcome the problem.

Answer»

The immediate adverse effects of drugs and alcohol abuse are manifested in the form of reckless behaviour, vandalism and violence. Excessive doses of drugs may lead to coma and death due to respiratory failure, heart failure or cerebral hemorrhage. A Combination of drugs or their intake along with alcohol generally results in overdosing and even deaths. The most common warning signs of drug and alcohol abuse among youth include drop in academic performance, unexplained absence from school/college, lack of interest in personal hygiene, withdrawal, isolation, depression,, fatigue, aggressive and rebellious behaviour, deteriorating relationships with family and friends, loss of interest in hobbies, change in sleeping and eating habits, fluctuations in w’eight, appetite, etc. There may even be some far-reaching implications of drug/alcohol abuse. If an abuser is unable to get money to buy drugs/alcohol he/she may turn to stealing. The adverse effects are just not restricted to the person who is using drugs or alcohol. At times, a drug/ alcohol addict becomes the cause of mental and financial distress to his/her entire family and friends.

The age-old adage of‘prevention is better than cure’ holds true here also. It is also true that habits such as smoking, taking drug or alcohol are more likely to be taken up at a young age, more during adolescence. Hence, it is best to identify the situations that may push an adolescent towards use of drugs or alcohol, and to take remedial measures well in time. In this regard, the parents and the teachers have a special responsibility. Parenting that combines with high levels of nurturance and consistent discipline, has been associated with lowered risk of substance (alcohol/drugs/tobacco) abuse. Some of the measures mentioned here would be particularly useful for prevention and control of alcohol and drugs abuse among adolescents.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

\(\frac{1}{2}^{-2}÷\frac{1}{2}^{-2}\)A) (1/2)3 B) -1 C) 1 D) – 2

Frame five questions using the picture clues. Begin with “Have you ever”.1. Write a story2. Visit the Tajmahal3. Cook briyani4. Watch a horror film5. Play Ten pin bowling6. Go swimming

Give an account on: i. Sacrum ii. Coccyx

New Market has employed Aryan Kumar to manage and maintain their networking architecture and wide area connectivity. Which type of job will best describe his job profile?

Reena wants to get employment opportunities based on IT. What are the options for employments?

Balance the following equations:(a) N2 + H2 → NH3(b) H2 + O2 → H2O(c) Na2O + H2O → NaOH(d) CO + O2 → CO2(e) Zn + HCl → ZnCl2 + H2

Balance the following equations. Also name the products formed. The first one is done for you.1. NaNO3 → NaNO2 + O2 Name of product(s)2. K + Cl2 → KCl 3. Ag + S → Ag2S 4. Mg + O2 → MgO 5. KClO3 → KCl + O2

What information do you get from the equation H2+ Cl2 → 2HCl ?

State what you would observe when the following substances are heated in a glass test tube:(i) Red lead(ii) Copper (II) carbonate

Balance the following chemical equations : (a) FeS + HCl → FeCl2 + H2S (b) Na2CO3 + HCl → NaCI + H2O + CO2(c) H2 + O2 → H2O (d) Na2O + H2O → NaOH

Write the molecular formula for the oxide and sulphide of following elements.(a) Sodium (b) Calcium (c) Hydrogen

Explain the following reaction with one suitable example for each.(a) Combination reactions(b) Decomposition reaction(c) Displacement reaction(d) Double decomposition reaction

Write your observations and name the products when(a) Zinc reacts with dilute hydrochloric acid.(b) Iron nails are added to an aqueous solution of copper sulphate.(c) An aqueous solution of barium chloride is added to dilute sulphuric acid.

Differentiate between:(a) Reactants and products(b) A balanced and an unbalanced chemical equation

(a) Define chemical reaction. (b) What is a chemical equation? (c) Why do we need to balance chemical equations?

Complete the following : XeF4 + H2O → ……………… + HF

State four conditions necessary for chemical reactions to take place.

XeF4 on partial hydrolysis produces : (a) XeF2 (b) XeOF2 (c) XeOF4 (d) XeO3

(a) Define chemical reaction.(b) What is a chemical equation?(c) Why do we need to balance chemical equations?

Define:(a) Radical(b) Valency(c) Molecular formula

What are the ways by which a chemical equation can be made more informative ?

What is variable valency ? Give two examples of elements showing variable valency.

Write the molecular formula for the following compounds and name the elements present.(a) Baking soda (b) Common salt(c) Sulphuric acid (d) Nitric acid

The valency of aluminium is 3. Write the valency of other radicals present in the following compounds.(a) Aluminium chloride(b) Aluminium oxide(c) Aluminium nitride(d) Aluminium sulphate

What are Saturn’s rings made of ?

How much time do the Sun’s rays take to travel from the space to the earth?

How much time do the Sun’s rays take to travel from the space to the earth?

Why is melting point of LiCl lower than NaCl?

Give the order in which the melting points of halides of sodium decrease and why?

Explain Sorption.

The matrix A = \(\begin{pmatrix}2&amp;-2&amp;-4 \\- 1 &amp;3&amp;4\\1&amp;-2&amp;-3\end{pmatrix}\) isA. Nonsingular B. Idempotent C. Nilpotent D. Orthogonal

Write the IUPAC names [Cr(NH3)4Cl2]+

Describe the principle of preparation of SO2 gas in the laboratory. Discuss the following properties of SO2- (a) Acidic properties (b) Bleaching properties (c) Oxidising properties and (d) Reducing properties.

Find the sum without operation 1 + 3 + 5(A) 9(B) 8(C) 7(D) 6

What are the factors on which the rate of reaction depends? Discuss each factor in brief.

What is meant by zero order reaction? Give examples.

Find the smallest square number that is divisible by each of the numbers 8, 15, and 20.

Find the smallest square number that is divisible by each of the numbers 4, 9, and 10.

What is manifestation?

Using factor theorem, factorize each of the following polynomial:y3 - 2y2 - 29y - 42

What is immunization?

What is tissue culture? What are the different types of tissue culture? Describe briefly.

What do you understand by vaccination and immunization?

Flowers of Vallisneria spp are (A) Anaemophilous (B) Entomophilous (C) Hydrophilous. (D) Zoophilous

Mention two methods of treatment of the disease.

Describe the different methods for treatment of cancer.

In your locality, if a person is addicted to alcohol, what kind of behavioural changes do you observe in that person? Suggest measures to overcome the problem.

The matrix A = \(\begin{pmatrix}2&-2&-4 \\- 1 &3&4\\1&-2&-3\end{pmatrix}\) isA. Nonsingular B. Idempotent C. Nilpotent D. Orthogonal