The pH indicator bromothymol blue is blue in an alkaline solution and yellow in an acidic solution. A slight increase in acidity, such as when CO2 gas is
added, causes a solution with the indicator to change from blue to yellow.
A solution with the indicator would turn from blue to yellow when which
combination of factors exists? Select the two correct answers.
A. A water plant in the solution is placed on a sunny windowsill.
B. Yeast cells and sugar are placed in the solution.
c. A person blows air into the solution through a straw.,
D. Algae in the solution are placed under a bright light.