Explore topic-wise InterviewSolutions in Current Affairs.

Correct option is (c) Al³⁺ > Mg²⁺ > Na⁺ > F > O^2-

Correct option is (b) Na⁺>Li⁺>Mg²⁺>Be²⁺

(a) Mg because Mg and …. a are present in large amount in sea water. 

(b) Si is used in solar cells. 

(c) Ba is most electropositive because electrospositive character increases down the group.

104 has three significant figures while 104.4 has four significant figures.

\(\because\) 1 g atom of Mg = 24 g

\(\therefore\) 2.5 g atoms of Mg = 24 × 2.5 = 60 g

Atomic mass of Ca = 40

40 g of calcium = \(\frac{1}{40}\) x 8 = 0.2 mol

One mole is the amount of a substance that contains as many particles as there are atoms in exactly 12 g of the carbon-12.

Formula mass of CaCl₂ = 40+2 x 35.5 

= 40 + 71 = 111 u

1. Name of the game : Nine Men’s Morris 

2. No of players: 2 

3. Type of game: Board game 

4. Things required: Board, buttons, beads, seeds etc. as pieces. 

5. How to play: Each player has nine pieces one set black and one set white Players take turns to place their pieces one at a time. If one player is able to place three ‘men’ in a row or column ‘a mill’ is formed. Once a mill is formed that player can remove his opponents men. Rules to be followed:

One cannot remove men in one’s opponent’s mill, unless he/she has no other men left on the board Once all men are placed on board you can start moving them only to an adjacent spot which is empty. When only three men are left, they can fly i.e. move to any vacant spot on the board. Deciding the winner: If a player has less than three men left or if he/she is unable to make a move, his opponent is declared the winner.

Electrolytic refining.

(i) Tea pot

(ii) The letter p

(iii) Peacock

An old mariner stopped one of the three guests who were going to attend a wedding. The wedding guest got annoyed and asked the ancient mariner, who had a grey beard and glittering eye, the reason for stopping him in that manner.

Poetic Devices :

Alliteration – grey beard and glittering eye.

The wedding guest told the ancient mariner that he was a close relative of the bridegroom. The guests had arrived and the doors of the bridegroom’s house had opened wide. The feast had been laid and the mariner could hear the happy sounds from that house.

The mariner held the hand of the wedding guest as if he had not listened to anything that the guest had said and started narrating a story that there was a ship. The wedding guest got annoyed and told the mariner to leave his hand. The ancient mariner quickly took away him hand.

Poetic Device :

his hand dropt he. Alliteration – He holds him with his skinny hand.

(a) of the hypnotic effect of the Mariner’s gaze. 

(b) listens obediently.

(c) he manages to get the Wedding Guest to stop and listen to his story.

(d) Simile. 

(a) To tell his story/to tell his story of misfortune/to unburden himself/to confess/to be rid of his guilt.

(b) Wedding Guest was under the spell/Mariner held him with his glittering eyes/mesmerized/hypnotized by the Ancient Mariner.

(c)  Shining/sparkling/captivating/mesmerizing.

(d) abcb.

Then the ancient mariner held him captive with his shinning eyes. He hypnotised him. The wedding guest could not say anything and started listening to the story take a three year old child. The mariner wish was fulfilled as he wanted the wedding guest to pay attention to his story.

Alliteration – (i) Stood still, (ii) holds him, (iii) hath his will

Simile – like a three years child. 

Molecular mass of a substance is defined as the average relative mass of its molecule as compared to the mass of an atom of C-12 taken as 12. It expresses as to how many times the molecule of a substance is heavier than 1/12th of the mass of an atom of carbon. 

For example, a molecule of carbon dioxide is 44 times heavier than 1/12th of the mass of an atom of carbon. Therefore the molecular mass of CO₂ is 44 amu. It is obtained by adding the atomic masses of all the atoms present in one molecule. 

Positive ions 1, Negative ions 1

Correct answer is (c) hydathodes

Correct answer is (b) bidirectional

Correct answer is (c) sucrose

(iii) 5-Chlorohexan-2-ol

Ethanol is used in 

i) Preparation of Alchoholic drinks 

ii) Preparing tincture iodine 

iii) Preparing cough syrup and tonics

All these are important chemical compounds used further by chemical industries.

• Ethyl Alcohol is used as a solvent for many organic solutes, especially which are insoluble in water.

• It is used in the preparation of perfumes.

• It is used in the manufacturing of gasohol, which is 90% mixture of petrol (gasoline) and 10% ethanol. It helps to save gasoline.

• Ethyl Alcohol is used in making tinctures and medical syrups.

• It is used in alcoholic beverages.

• It is used as a solvent for paints, varnishes, dyes etc.

• It is used in the production of many organic compounds.

Correct option is (a) NH₂^-

(a) NH₃ will have larger value of a because of H – bonding. 

(b) NH₃ will have larger value of b due to larger molecular size.

A gas with a = 0 means absence of intermolecular forces. Hence such a gas cannot be Liquified.

At low temperature and high pressure intermolecular attractions cannot be neglected, the observed pressure P is smaller than the ideal pressure Pi. 

Therefore, Pi = P + p = P + an²/V₂.

As volume of gas molecules is not negligible as compared to total volume of the gas the ideal volume Vi is smaller than the observed volume. Therefore, Vi = V + v = V - nb.

 (iii) pressure decreases

(a) High compressibility is due to large empty space between the gas molecules. 

(b) Due to absence of attractive forces between the molecules, they can easily separate from one another.

(ii) surface tension

NH₃

Molecular mass of NH₃= Atomic mass of N + 3 x Atomic mass of H

Molecular mass of Nitrogen = 14

Molecular mass of hydrogem= 1
= 14 + 3 x 1
= 17 g

Answer is (iv) 1 m

Answer is (iii) 0.005 M

1. False - The head of a matchstick contains potassium chlorate and antimony tri sulphide.

2. True

3. True

4. False - Urea is an important fertilizer in agriculture, but ammonia is the material used for the production of urea.

5. True

6. False - Catalysts are used to alter the speed of a chemical reaction and increase the reaction rate.

1. The nitrates of alkali metals do not produce reddish brown nitrogen dioxide on heating. 

2. The most common ones are sodium nitrate and potassium nitrate.

i. b 

ii. a 

iii. d 

iv. c

1. Photosynthesis is a process in which light energy from the sun is used by the plants to prepare starch from carbon dioxide and water. 

2. The sunlight uses the chemical reaction between carbon dioxide and water, which finally ends up in the production of starch (photo means light and synthesis means production). These chemical reactions in used by light are called as photochemical reactions.

Tarnishing of metal articles: 

Shiny metal surfaces and other articles lose their shining appearance due to chemical reactions on the surface. For example, silver articles become black on exposure to atmospheric air.

Similarly, brass vessels which contain copper as one of constituents develop a greenish layer on exposure to air for a long time. This is due to a chemical reaction between copper and moist air to form basic copper carbonate and copper hydroxide.

1. Yeast is a key ingredient in the production of baked goods. 

2. Yeast is a bio – organic catalyst carbon dioxide is generated by the yeast as a result of the breakdown of fermentable sugars in the dough and makes cakes to rise.

A concentrated solution of sodium chloride called Brine is electrolysed to produce chlorine and hydrogen gases along with sodium hydroxide. This is a very important reaction to produce chlorine industrially.

Endothermic reaction

(b) Todomethane + Ethanol

Condition required for a chemical reaction to take palce :

Chemical reactions can be done through:

1. Physical contact 

2. Solution of reactants 

3. Electricity 

4. Heat 

5. Light 

6. Catalyst

1. Chemical Reactions Based On Solution Of Reactants: 

When we mix two substances (Reactants) in solution form, the chemical reaction takes place to form new substances (Products).

Example: 

• Take small amount of solid silver nitrate and sodium chloride in a test tube. The reactants in solid state have no reactions.
• Dissolve the same reactants in water in separate test tubes. 
• Mix both the solutions. Silver nitrate solution reacts with sodium chloride solution to form a white precipitate of silver chloride and sodium nitrate solution. 
• From the above reaction, we infer that some chemical reactions proceed only in solution form not in solid form.

2. Chemical Reaction Based On Electricity :

• When electricity is passed through water containing small amounts of sulphuric acid, hydrogen and oxygen gases are liberated. 
• Similarly, a concentrated solution of sodium chloride called Brine is electrolysed to produce chlorine and hydrogen gases along with sodium hydroxide.
• This is a very important reaction to produce chlorine industrially. 
• From the above two reactions, we infer that some chemical reactions proceed only by the passage of electricity. 
• Hence, such reactions are called as electrochemical reaction or electrolysis.

3. Chemical Reactions Based On Light: 

Sunlight is important not only for us but also for plants as welll. As you know photosynthesis is a process in which light energy from the sun is used by the plants to prepare starch from carbon dioxide and water.

Example: 

The sunlight uses the chemical reaction between carbon dioxide and water, which finally ends up in the production of starch (photo means light and synthesis means production). These chemical reactions is used by light are called as photochemical reactions.

Chemical changes are otherwise called as chemical reactions, because one or more substances (Reactants) undergo a reaction to form one or more new substances (Products). Reactant(s) → Product(s)

1. Yes, Rajasekar is more concerned over his family health than saving money. 

2. Rajasekar know that the air pollution from nearby chemical industry would be harmful and affect his family health. 

3. Environmentally sensitive, awareness, caring and correct decision

The conditions required for a chemical reaction to take place: 

1. Physical contact 

2. Solution of reactants 

3. Electricity 

4. Heat 

5. Light 

6. Catalyst