Describe the preparation, collection, and properties of hydrogen chloride gas.

Okay, let's tackle Question 3 from the image.

Question 3:

a) The reagents used to prepare hydrogen chloride gas in the laboratory are:

• Concentrated sulfuric acid ($\text{H}_2\text{SO}_4$)
• Sodium chloride ($\text{NaCl}$)

b) The balanced chemical equation for the reaction is:

$$\text{NaCl(s)} + \text{H}_2\text{SO}_4\text{(l)} \rightarrow \text{NaHSO}_4\text{(s)} + \text{HCl(g)}$$

This reaction typically occurs when heated.

c) Hydrogen chloride gas is denser than air, so it is collected by downward delivery (or upward displacement of air).

d) One physical property of hydrogen chloride gas is that it is a colorless gas. Other properties include being pungent-smelling, highly soluble in water, and denser than air.

e) One chemical property of hydrogen chloride gas is that it is acidic. When dissolved in water, it forms hydrochloric acid, which turns blue litmus paper red. It also reacts with bases and carbonates.