Evolution of Gas

Q.

Formation of gas bubbles in a liquid during a reaction is a called ___

1. Reduction

2. Redox

3. Oxidation

4. Heating

Q.

Dilute hydrochloric acid is added to granulated zinc taken in a test tube. The following observations are recorded. Point out the correct observation.

1. The surface of metal becomes shining.

2. The reaction mixture turns milky.

3. Odour of a pungent-smelling gas is recorded.

4. A colourless and odourless gas is evolved.

Q.

State the chemical property in each case on which the following uses of baking soda are based
(i) as an antacid.
(ii) as a constituent of baking powder. [3 MARKS]

Q.

When washing soda is treated with hydrochloric acid, it gives off colourless gas with lot of effervescence. What is the name of that gas formed?

1. $C{O}_2$

2. $O_2$

3. $CO$

4. $C{l}_2$

Q.

Mixing of powdered Sulphur with iron filings is a chemical change.

1. True
2. False

Q.

Limestone changes into quicklime and carbon dioxide on strong heating. This is an example of a chemical change

1. True
2. False

Q.

Electrolysis of water gives dioxygen gas - True or False?

1. False
2. True

Q.

Name the gas evolved when zinc is dropped in diluted sulphuric acid.

Q.

Write true or false for the following statements.

The formation of a mixture involves energy change.

1. True
2. False

Q. Zinc dissolves in hydrochloric acid with the evolution of hydrogen gas.

1. Chemical
2. Physical
3. Both $A$ and $B$
4. None of these

Q. What is the name of the chemical compound which is formed when sulphur dioxide is treated with water?

1. Sulphuric acid
2. Sulphurous acid
3. Sulphonic acid
4. Hydrosulphuric acid

Q. is also known as laughing gas.

1. Ammonia
2. Calcium oxide
3. Sodium sulphate
4. Nitrous oxide

Q.

Identify X and Y in the reaction given below.

$\text{Zinc(s) + Hydrochloric acid(aq)}\to \text{X + Y}$

1. X- Zinc chloride, Y- Hydrogen
2. X- Zinc hydroxide, Y- Hydrochloric acid
3. X- Zinc chloride, Y- Hydrochloric acid
4. X- Zinc hydroxide, Y- Chlorine

Q. Upward arrow in a chemical equation represents _________.

1. formation of a precipitate
2. evolution of a gas
3. heat absorbed
4. heat released

Q.

What reaction takes place when silver nitrate is kept in the presence of sunlight

Q. Iqbal treated a lustrous, divalent element M with sodium hydroxide. He observed the formation of bubbles in reaction mixture. He made the same observations when this element was treated with hydrochloric acid. He find that the produced gas is:

1. $H_2$
2. None of the above
3. $C{l}_2$
4. $O_2$

Q.

When lead nitrate is heated, the brown coloured fume coming out is due to the release of ____ gas.

1. Sulphur dioxide

2. Nitrogen monoxide

3. Sulphur trioxide

4. Nitrogen dioxide

Q.

Which of these chemical reactions produce a gas?

1. Zinc reacting with dilute sulphuric acid

2. Iron dropped into copper sulphate solution

3. Silver nitrate is added to a sodium chloride solution

4. Ammonia gas reacting with hydrochloric acid

Q. Hina dipped a glass rod in $\text{conc. HCl}$ and observed faint fumes. These fumes became dense when she dipped the same glass rod in ${\text{NH}}_3$ gas. The possible reason for Hina's observation is:

1. the sublimation of ${\text{NH}}_4\text{Cl}$ which is formed when $\text{HCl}$ reacts with ${\text{NH}}_3$.
2. the condensation of ${\text{NH}}_4\text{Cl}$ which is formed when $\text{HCl}$ reacts with ${\text{NH}}_3$.
3. the sublimation of ${\text{NH}}_4\text{OH}$ which is formed when $\text{HCl}$ reacts with ${\text{NH}}_3$.
4. the evaporation of ${\text{NH}}_4\text{OH}$ which is formed when $\text{HCl}$ reacts with ${\text{NH}}_3$.

Q. Hina dipped a glass rod in $\text{conc. HCl}$ and observed faint fumes. These fumes became dense when she dipped the same glass rod in ${\text{NH}}_3$ gas. The possible reason for Hina's observation is:

1. the sublimation of ${\text{NH}}_4\text{Cl}$ which is formed when $\text{HCl}$ reacts with ${\text{NH}}_3$.
2. the evaporation of ${\text{NH}}_4\text{OH}$ which is formed when $\text{HCl}$ reacts with ${\text{NH}}_3$.
3. the condensation of ${\text{NH}}_4\text{Cl}$ which is formed when $\text{HCl}$ reacts with ${\text{NH}}_3$.
4. the sublimation of ${\text{NH}}_4\text{OH}$ which is formed when $\text{HCl}$ reacts with ${\text{NH}}_3$.

Q.

The reddish-brown fume coming out when lead nitrate is heated is known as

1. Nitrogen trioxide

2. Nitrogen monoxide

3. Nitrogen

4. Nitrogen dioxide