Which pair of substances would most likely result in the production of a gas when reacting with an acid?
a. litmus and methyl orange
b. base and salt
c. metal and carbonate
d. carbon dioxide and water

Answer;

C. metal and carbonate

Explanation;

-Both metals and carbonates reacts with acids to produce gases.

-Metals for instance, react with acids to yield a salt and hydrogen gas. For example when zinc metal reacts with hydrochloric acid, a salt of zinc chloride and hydrogen gas are formed.

-Carbonates on the other hand reacts with acids to produce a salt, water and carbon dioxide gas. For example sodium carbonate reacts with sulfuric acid to produce a salt, sodium sulfate, water and carbon dioxide gas

the product of the pressure and volume is also constant