H₂O₂ restores the colour of old lead paintings by:

1. Converting PbO₂ to Pb

2. Oxidising PbS to PbSO₄

3. Converting PbCO₃ to Pb

4. Oxidizing PbSO₃ to PbSO₄

The incorrect statement among the following regarding hydrogen is -

1. Hydrogen never acts as a cation in Ionic salts

2. Hydronium ion, H₃O⁺, exists freely in a solution

3. Dihydrogen does not act as a reducing agent

4. Hydrogen has three isotopes of which Protium is the most common

 Hardness of water cannot be removed by -

1. Clark's method

2. Adding washing soda

3. Calgon process

4. Filtration

A compound that acts as both reducing and oxidising agent is-

1. H₂SO₄

2. H₂O₂

3. KOH

4. KMnO₄

A 1000 g aqueous solution of CaCO₃ contains 10 g of calcium carbonate. The hardness of the solution is:

1. 10 ppm

2. 100 pm

3. 1000 ppm

4. 10000 ppm

H₂O₂ is prepared in the laboratory by the reaction of :

1. MnO₂ with dilute cold H₂SO₄

2. BaO₂ and  CO₂ bubbling through cold water

3. PbO₂ with an acidified solution of KMnO₄

4. Na₂O₂ with boiling water

On bubbling CO₂ through a solution of barium peroxide in water:

1. O₂ is formed

2. H₂CO₃ is formed

3. H₂O₂ is formed

4. H₂ is formed

The correct statement among the following regarding perhydrol is -

1. It is 30% H₂O₂ or 100 vol. H₂O₂

2. Its molarity is 8.8 M

3. It is used as an antiseptic and a germicide

4. All of the above

The bleaching properties of H₂O₂ are due to its: 

1. Reducing properties

2. Oxidising properties

3. Unstable nature

4. Acidic nature

When zeolites (hydrated sodium aluminum silicate) is treated with hard water, the sodium ions are exchanged with:

1. H⁺ ion

2. Ca²⁺ ion

3. ${\mathrm{SO}}_4^{2-}$ ion

4. OH^- ion