pH of acids, bases and salts

Exercise 2

   

Calculate the $pH$ of a acide perchlorique   0.42 $\frac{g}{L}$ solution

Strong acid Number of moles in $1\;L$: $n$ $=$ $\frac{m}{M}$ (with $m$ = 0.42$ \;g$ and $M$ = 100.46) = 0.0042$\;mol$ $pH$ $=$ $-log\;c$ = $-log \;$0.0042= 2.38