How much more acidic is a solution of pH 3 compared with a solution of pH 6?

1 Answer
Oct 24, 2016

The solution whose #pH=3# is #1000# times as acidic as the solution whose #pH=6#.

Explanation:

By definition, #pH=-log_(10)[H_3O^+]#. A solution whose #pH=1# is ten times more acidic than the solution whose #pH=2#.

Given the logarithmic scale, if #pH=3# this is #10^3# times as acidic as the solution whose #pH=6#.

To give numbers, #pH=3#, #[H_3O^+]=10^-3*mol*L^-1#.

#pH=6#, #[H_3O^+]=10^-6*mol*L^-1#. And clearly the former is #10^3# as acidic.

Back in the day, students routinely used log tables before the advent of electronic calculators to perform mulitplications and divisions. I can't say say that I really miss it; there was far too much arithmetic.