Anna is conducting an experiment using a pH indicator that is red at low pH, green at neutral pH and purple at high pH. She starts with a green solution. When she adds compound X to her solution it turns purple. Then she adds compound Z to the solution and it turns green. She adds more Z, the solution remains green. These observations suggest X is ________ and Z is ________.

Question

Quizplus · Accepted Answer

X is a base because it increases the pH of the solution, turning it from green to purple. Z is a buffer because it keeps the pH of the solution at a neutral green color, even when more of it is added.

Anna Is Conducting an Experiment Using a PH Indicator That