Hydrogen from Acids

Q. Question 43.
In the following schematic diagram for the preparation of hydrogen gas as shown in the figure, what would happen if the following changes are made?

1. In place of zinc granules, same amount of zinc dust is taken in the test tube.
2. Instead of dilute acid, dilute hydrochloric acid is taken.
3. In place of zinc, copper turnings are taken.
4. Sodium hydroxide is taken in place of dilute sulphuric acid and the tube is heated.

Q.

Why nitric acid is not used is not used for the preparation of hydrogen gas?

1. Because it is dibasic

2. Because it is a strong oxidizing agent.

3. Because it is a strong reducing agent.

4. Because it is monobasic

Q.

Why is Sulphuric acid used instead of Hydrochloric acid?

Q.

What is the role of ${\mathrm{H}}_2{\mathrm{SO}}_4$?

Q.

Why is hot concentrated Sulphuric acid not used in the preparation of Hydrogen ?

Q.

Why is the electrolysis of sulphuric acid called electrolysis of water?

Q.

Give reason:

Acidulated water is used for electrolysis.

Q.

Which amongst the following will not displace hydrogen gas from dilute hydrochloric acid?

1. Magnesium

2. Zinc

3. Aluminium

4. Copper

Q. The work done in an open vessel at 300k, when 56g iron react with dilute HCL is

Q.

Assertion: When a piece of copper metal is added to dilute sulphuric acid, the solution turns blue.

Reason: Copper reacts with dilute sulphuric acid to form blue Copper(II) sulfate solution.

1. Both assertion and reason are false

2. The assertion is true but the reason is false

3. Both assertion and reason are true. The reason is the correct explanation of the assertion.

4. Both assertion and reason are true. The reason is not the correct explanation of the assertion.

Q.

What is the ratio of HNO₃ and HCl in aqua regia? What are the applications of aqua regia?

Q.

Why is nitric acid not used in the preparation of hydrogen ?

Q. Why only dilute acids are used to prepare hydrogen?

Q.

Hydrogen may be prepared in the laboratory by the action of a metal on an acid.

(a) Which of the metals copper, zinc , magnesium or sodium would be the most suitable ?

(b) Which of the acids dilute sulphuric, concentrated sulphuric, dilute nitric acid and concentrated nitric would you choose ? Explain why you would not use the acids you reject.

(c) How would you modify your apparatus to collect dry hydrogen ? Which drying agent would you employ for this purpose ?

Q.

Which of the following acids is not used in the preparation of hydrogen from metals?

1. Nitric acid

2. Hydrochloric acid

3. Sulphuric acid

Q.

Nitric acid, even in its diluted form, is not used in the preparation of hydrogen from metals because metals on reaction with nitric acid can't replace the hydrogen atom.

1. True

2. False

Q.

During local action in simple voltaic cell:

1. tiny hydrogen bubbles collect at the copper plate

2. a large number of local cells are formed

3. a large number of local cells are formed at the copper plate

4. all the above

Q.

What is aqua regia and where do we use it?

Q.

Explain the following:
All glass apparatus is used in the laboratory preparation of nitric acid.

Q. is generally used to dissolve gold.

1. Hydrochloric acid
2. Aqua regia
3. Nitric acid
4. Sodium hydroxide

Q.

The oxidizing properties of Nitric Acid is due to

1. Nascent Hydrogen

2. Nascent Oxygen

3. Nascent Chlorine

4. The Nitrate Ion

Q.

Explain nitric acid fumes in moist air.

Q.

Sulphuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ is a strong acid and is extremely useful both in the industry and in the laboratory. It forms two types of salts on reacting with a base. These are acid salts and normal salts. Care must be taken while diluting the acid with water. It is done by adding acid drop wise to water taken in a beaker and not water to the acid. Why does conc. H₂SO₄ form Blisters on the skin?

Q.

Nitric acid being a strong oxidizing agent is used in the preparation of hydrogen.

1. True
2. False

Q. When the stopper of a bottle full of hydrogen chloride gas is opened, fumes can be seen coming out. Why does this happen?

1. It reacts with the bottle to release fumes.
2. None of these
3. There is an immediate reaction between hydrogen chloride gas and water vapour in the air.
4. Hydrogen chloride is a noble gas.

Q. Aqua regia contains part(s) of concentrated $HCl$ and part(s) of concentrated $HN{O}_3$.

1. 3
2. 2
3. 1
4. 4

Q. iron + sulphuric acid - ferrous sulphate + hydrogen

Q. A reducing agent is a substance that can ______ electrons.

1. gain
2. lose
3. share
4. remove

Q.

Give two industrial applications of sulphuric acid.

Q. Question 37
Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid, whereas copper does not. Explain why?