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Arrhenius Theory –

Acids are substances which – dissociate in aqueous solution to give H⁺ ions.

Strong acids dissociate – almost completely, while weak acids dissociate partially. 

1.  Nitric acid

2. Zinc hydroxide

3. Sulphuric acid

4. Calcium Hydroxide

5. Acetic acid

1. K₂CO₃ is a salt of a strong base (KOH) and weak acid (H₂CO₃ ). Hence its aqueous solution will be basic in nature. It will have no effect on blue litmus solution.

2. KCl is a salt of a strong acid (HCl) and a strong base (KOH). Hence its aqueous solution will be neutral in nature. It will have no effect on blue litmus solution.

3. NH₄NO₃ is a salt of a strong acid (HNO₃) and weak base (NH₄OH). Hence its aqueous solution will be acidic in nature. It will turn blue litmus solution red. 

1. Ca(HCO₃)₂ + 2HCl → CaCl₂ + 2H₂O+ 2CO₂ 

2. CaCO₃ + 2HNO₃ → Ca(NO)₂ + H₂O+ CO₂

3. Na₂SO₃ + H₂SO₄ (dil.) → Na₂SO₄ + H₂O+ SO₂

4. ZnS + H₂SO₄  → ZnSO₄ + H₂S 

H₂SO₄ → H⁺ + HSO₄⁺ (Bisulphate ion)

HSO₄^– → H⁺ + SO₄²⁺ (Sulphate ion)

pH scale: The pH of a solution is defined as the negative logarithm of hydrogen ion concentration in moles per litre.

pH = - log [H⁺(aq)]

The pH scale is a continuous scale and the value of pH varies between 0 to 14.

The pH of pure or neutral water is 7. Solutions having pH less than 7 are acidic in nature and the solutions with pH more than 7 are basic in nature.

The reason for the formation of the respective acids from cone. H₂SO₄ is the volatility of the acid formed. At room temperature or above HCl is a gas while HNO₃ , which is a liquid at room temperature, volatileses at the reaction temperature (w 200°C). 

The strength of an acid or an alkali can be tested by using a scale called the pH scale (0- 14) which gives the measure of hydrogen ion concentration in a solution

a)  The acids are HCl and lemon juice.

b) The nature of the solution which turns pink colour with phenolphthalene solution is basic.

c) The neutral solutions are distilled water and NaCl. 

d) The strongest acid is HCl and the strongest base is NaOH.

Add a drop of pH solution to the solution whose pH is to be determined or dip the pH paper into it. The pH value of the solution can be determined by comparing with the pH color chart.

NaOH + HCI→ NaCl + H₂O

1. Take a few crystals of copper sulphate in a dry test tube and heat the test tube. 

2. We observe water droplets on the walls of the test tube and salt turns white. 

3. Add 2 – 3 drops of water on the sample of copper sulphate obtained after heating. 

4. We observe the blue colour of copper sulphate crystals is restored.

To salt, add few drops of dilute HCI or H₂SO₄, if colourless gas is evolved with brisk effervescence and on passing it through lime water, the lime water turns milky, the gas is CO₂ and salt is a carbonate of metal.

(a) Basic 

(b) pH value decrease. Curd is lactic acid 

(c) (i) Lime water 

(ii) Blood

Salt that contains water of crystallisation.

Washing soda - Na₂CO₃.10H₂O

Gypsum-CaSO₄.2H₂O

Plaster of paris- CaSO₄.1/2H₂O.

Acids are substances which can increase the concentration of hydrogen (H⁺) ions in an aqueous solution.

(a) H⁺ and Cl^-

(b) H⁺ and NO^-₃ 

(c) H⁺

(i) When 18 g of water is added to 56 g of calcium oxide, calcium oxide combines with water to form calcium hydroxide Ca(OH)₂

(ii) The mass of calcium hydroxide formed is 74 g.

(iii) In this activity the total mass of reactants, Calcium oxide + Water = 56 g +18 g = 74 g.

It is equal to the mass of the product formed. Ca(OH)₂ = 74g.

This activity verifies the Law of Conservation of Matter, i.e., in a chemical reaction, the total weight of the reactants is same as the total weight of the products formed due to the chemical reactions.

1. When hydrated salt is heated water droplets form inside the walls of test tube and sometimes blue or green colour salt turns into white colour. 

2. When unhydrated salt is heated it does not form water droplets inside the test tube walls and colour also does not change.

Fe + 2HCI → FeCl₂ + H₂

(1) Lead sulphate from lead carbonate. 

PbCO₃ + HNO₃ → Pb(NO₃)₂ + H₂O + CO₂ 

Pb(NO₃)₂ + H₂SO₄ → PbSO₄ + 2HNO₃

(2) Sodium sulphate using dilute sulphuric acid.

Na₂CO₃ + H₂SO₄ (dil) → Na₂SO₄ + H₂O+ CO₂

(3) Copper chloride using copper carbonate.

CuCO₃ + HCl(dil) → CuCl₂ + H₂O + CO₂ (Insoluble)

HCl → H⁺ + Cl^-

H⁺ + H₂O → H₃O⁺ (Hydronium ion)

The compound or salt S is copper sulphate CuSO₄

CuO + H₂SO₄ → CuSO₄ +  FlO 

Reaction in which a single reactant breaks down to give simpler products.

Thermal decomposition

CaCO₃+heat  → CaO+CO₂  

Electrolytic decomposition-

2H₂O+ Electric current → 2H₂+O₂  

Detailed Answer:

In a decomposition reaction, a single reactant breaks down into two or more simpler products. When a decomposition reaction is carried out by heating, it is called thermal decomposition reaction.

CaCO₃(s) + heat  → CaO(s) + CO₂(g)

CaCO₃(s)-Calcium carbonate

CaO(s)-Calcium oxide

 CO₂(g)-Carbon dioxide

When a decomposition reaction is carried out with the help of electric current, the process is called electrolysis.

2H₂O(l) + Electric current →2H₂(g) +O₂(g)

2H₂O(l)-Water

2H₂(g)-Hydrogen gas

O₂(g)-Oxygen gas

In chemicals, pesticides, glass, varnish and printing industries.

Andhra Pradesh, Gujarat, Maharashtra, Assam and Andaman and Nicobar Islands.

Orissa, Andhra Pradesh, Chhattisgadh, Gujarat, Jharkhand and Maharashtra.

Biotic and abiotic materials when decompose under the earth transform into a particular chemical constitution due to pressure and heat of the earth. These are called minerals.

A. Metallic Minerals: e.g. – copper, gold. zinc,

B. Non-metallic minerals: e.g. – ruby, lime. silica,

C. Rr genera ng minerals: e.g.- coal, mineral dl, reading

A. Metallic Minerals: e.g.- copper, gold, zinc,

B. Non-metallic minerals: e.g. – ruby, lime, silica,

C. Power generating minerals: e.g. – coal, mineral oil, radium

Because minerals found under the earth are never pure.

Correct option  (C)  6.0 

It is because HCl and HNO₃ ionize in aqueous solution whereas ethanol and glucose do not ionize in aqueous solution

(C)    CH₃OH

(a) False

(b) False

(c) False

CH₃-CH = CH-CN + diBAL-H → CH₃CH=CH-CHO

one that has a hydrogen atom attached to a strongly electronegative element such as oxygen

The statement is-

False

(a) Usual number of valence elec trons is 8; Valency is 0 (zero).

(b) The number of valence electrons remains the same .

(a) Phenol : It gives FeCl₃ test(violet colour) 

Alcohol : It doesn't give this test 

(b) Benzaldehyde: 

• It gives tollen's test 
• It doesn't give Fehling test. 

Propanal : 

• It also give tollen's reagent test 
• It gives fehling solution test 

(c) Acetic acid : 

• It doesn't gives tollen's reagent . 
• It doesn't give fehling's test 

Formic acid : 

• It gives tollen's test 
• It gives fehling test.

The number of valence electrons in the atoms of first element in a period is- 

(a) 1

The usual number of valence electrons in the atoms of the last element in a period is-

(b) 8

potential energy and kinetic energy.

An element belongs to period 2 and group 2 the number of valence electrons in the atoms of this element is 2.

Bond polarization that takes place through space and through the bonds of the molecule is called the  inductive effect. 

The group number and period number respectively of an element with atomic number 8 is 6, 2.

(i) Li and Na have a single electron in the outermost shell. They can easily lose 1 electron and produce cation which causes chemical reactions which are explosive in nature.

(ii) Na and Mg both lie in the same period so along the period atomic size decreases. So, the size of Mg is smaller than Na.

(iii) Electronegativity of F is more than Cl i.e. F has more affinity to attract electrons because of its small size due to this F is more reactive than Cl.

Because they are converted to water-soluble salts.