Which carbonate mineral reacts readily with cool dilute hydrochloric acid (HCl) to produce visible bubbles of carbon dioxide gas? Dolomite Calcite Quartz Plagioclase

The carbonate mineral that reacts readily with cool dilute hydrochloric acid (HCl) to produce visible bubbles of carbon dioxide gas is **Calcite**.

When hydrochloric acid comes into contact with calcite, a reaction occurs that produces calcium chloride, water, and carbon dioxide gas. This reaction is often used as a field test to identify the presence of calcite in rocks and minerals. The reaction can be represented as:

$$\text{CaCO}_3 + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} + \text{CO}_2$$

This reaction is not as vigorous with dolomite, and quartz and plagioclase are not carbonate minerals, so they do not react with HCl in the same way.