Question

Calculate the pH and pOH of each of the following solutions.

1) [H3O+]= 1.9×10−8 M
2) [H3O+]= 1.0×10−7 M
3) [H3O+]= 2.3×10−6 M

Answer 1

$pH=-log_{10}[H^{+}]$

$pH+pOH=14$

1) $pH= -log_{10}[1.9×10^{-8}]=7.7$

$pOH=14-7.7= 6.3$

2) $pH= -log_{10}[1.0×10^{-7}]=7$

$pOH=14-pOH=14-7=7$

3) $pH=-log_{10}[2.3×10^{-6}]=5.6$

$pOH=14-5.6=8.4$