Study for the Georgia High School Physical Science Test. Prepare with flashcards and multiple-choice questions, detailed hints and explanations included. Get ready for your exam!

Multiple Choice

Which of the following statements about bases is true?

Bases raise the OH- concentration when dissolved in water, which makes the solution basic and gives it a pH above 7. This hydroxide-ions idea is what defines a base in aqueous solution, and it explains why bases turn red litmus blue and why their pH is greater than 7. The other statements don’t fit: acids produce hydronium ions (H3O+) in water, not bases; a base’s pH is not less than 7, it’s greater than 7; and bases do interact with litmus by turning blue, so saying they do not react with litmus is incorrect.

Bases raise the OH- concentration when dissolved in water, which makes the solution basic and gives it a pH above 7. This hydroxide-ions idea is what defines a base in aqueous solution, and it explains why bases turn red litmus blue and why their pH is greater than 7.

The other statements don’t fit: acids produce hydronium ions (H3O+) in water, not bases; a base’s pH is not less than 7, it’s greater than 7; and bases do interact with litmus by turning blue, so saying they do not react with litmus is incorrect.