Calculate the pH value of the following
0.001 M HCI

Explanation

Since HCl is a strong acid, it is assumed to be completely ionised. Therefore, `[H_(3)O^(+)] = [HCl] = 0.001M = 1xx 10^(-3) mol L^(-1)`
Therefore, `pH= -log_(10)[H_(3)O^(+)]`
`= -log_(10)(1.0 xx 10^(-3))`
`= -(-3) log_(10)10`
=3 (as `log_(10)10=1`)