Please someone help my test is timed.
What is litmus paper used for?

A.) To indicate if all the reactants have been used up

B.) To determine if a chemical reaction has occurred

C.) To determine pH

D.) To detect the presence of water

The anser choice is c ph because when you dip it in a substance it changes color due to the pH

Explanation:

The anser choice is c ph because when you dip it in a substance it changes color due to the pH

it would be a gas formation

the right answer is c i just did the question.