Compared to a Solution of PH 9, a Solution of PH

Question

Compared to a solution of pH 9, a solution of pH 7 is _______.
A) 2 times more acidic
B) 20 times more acidic
C) 100 times more basic
D) 20 times more basic
E) 100 times more acidic

Accepted Answer

The pH scale is logarithmic, meaning each whole pH value below 7 is 10 times more acidic than the next higher value. Therefore, moving from pH 9 to pH 7 represents a 10^2 or 100 times increase in acidity.