Question

Small quantities of hydrogen gas can be prepared in the laboratory by the following reaction, except:

a) Zinc reacting with hydrochloric acid
b) Electrolysis of water
c) Sodium reacting with sulfuric acid
d) Heating magnesium with steam

Answer 1

The correct answer is c) Sodium reacting with sulfuric acid. Zinc reacting with hydrochloric acid, electrolysis of water, and heating magnesium with steam can all produce hydrogen gas in the laboratory.

Step-by-step explanation:

The correct answer is c) Sodium reacting with sulfuric acid. Small quantities of hydrogen gas can be prepared in the laboratory by the following reactions:

1. Zinc reacting with hydrochloric acid: This is a single-displacement reaction where zinc metal reacts with hydrochloric acid to give off hydrogen gas.
2. Electrolysis of water: This is the decomposition of water into hydrogen and oxygen gases using an electric current.
3. Heating magnesium with steam: This is a redox reaction where magnesium reacts with steam to produce magnesium oxide and hydrogen gas.

However, sodium reacting with sulfuric acid does not produce hydrogen gas. Instead, it produces sodium sulfate and hydrogen gas.