Question

What is the difference in hydrogen ion concentration comparing solutions with a pH of 2 and pH of 4?

Answer 1

A hundred fold difference in `H_3O^+` concentration applies

Explanation:

`pH=-log_10[H_3O^+]`. And thus each `pH` unit represents a tenfold difference in `[H_3O^+]`, i.e. hydrogen ion concentration.

Thus if `pH=2`, `[H_3O^+]=10^(-2)*mol*L^-1` `=` `0.01*mol*L^-1`

And if `pH=4`, `[H_3O^+]=10^(-4)*mol*L^-1` `=` `0.0001*mol*L^-1`.

Thus when `pH=2`, `[H_3O^+]` is `100xx` more concentrated than when `pH=4`.