Which of the following is a characteristic property of acids?

A.

Turn litmus paper blue

B.

Bitter taste

C.

pH value above 7

D.

React with metals to produce hydrogen gas

Correct answer is D

Acids are substances that can donate protons (H+) in aqueous solutions. When acids react with certain metals, they can release hydrogen gas (H2) as one of the products. This is a common behavior of many acids and can be used to distinguish them from other substances.