Answer to Question #169350 in Math for John

Question

 8                     Given that pH = - log [H+]

(a)              Find the pH of a solution which has a [H⁺] concentration of 

                                               i.     0.01 mol dm^-3

                                             ii.     0.004 mol dm^-3

            Determine the [H⁺] concentration of a solution with a pH of 3.8

Answer 1

(a)

i.

$$pH=-\log(0.01)=2$$

ii.

$$pH=-\log(0.004)=2.398$$

(b)

$$pH=-\log[H^+]=>[H^+]=10^{-pH}$$

$$[H^+]=10^{-3.8}=0.0001585\ mol\cdot dm^{-3}$$