How much more hydrogen ions does a solution with a pH of 3 has more than a solution with a pH of 6?

Question

Please answer the question above and explain how you got the solution. Thanks!

Answer 1

pH is a log-scale by definition. Thus a pH of 3 means 10-3 moles/L of H-ion, while pH of 6 means 10-6 moles/L of H-ion. Thus, the pH3 concentration is 1000 times the pH6 concentration.

Answer 2

formula for pH:

pH = -log10([H+])

the difference between the two pH values is 3, which means 3 orders of magnitude (10^3 = 1000)

the long way:

pH 3 , [H+] = 10^-3
pH 6 , [H+] = 10^-6

10^-3 / 10^-6 = 10^3 = 1000