Em tham khảo nha:
\(\begin{array}{l}
a)\\
{\rm{[}}O{H^ - }{\rm{]}} = {C_M}NaOH = 0,02M\\
pOH = - \log (0,02) = 1,7\\
pH = 14 - 1,7 = 12,3\\
b)\\
{\rm{[}}{H^ + }{\rm{]}} = 2{C_M}{H_2}S{O_4} = 0,1M\\
pH = - \log (0,1) = 1\\
c)\\
{\rm{[}}O{H^ - }{\rm{]}} = 2{C_M}Ba{(OH)_2} = 0,02M\\
pOH = - \log (0,02) = 1,7\\
pH = 14 - 1,7 = 12,3\\
d)\\
{n_{HCl}} = 0,15 \times 0,2 = 0,03\,mol\\
{C_M}HCl = \dfrac{{0,03}}{{0,15 + 0,05}} = 0,15M\\
{\rm{[}}{H^ + }{\rm{]}} = {C_M}HCl = 0,15M\\
pH = - \log (0,15) = 0,82\\
e)\\
{n_{NaOH}} = 0,15 \times 0,2 = 0,03\,mol\\
{C_M}NaOH = \dfrac{{0,03}}{{0,15 + 0,05}} = 0,15M\\
{\rm{[}}O{H^ - }{\rm{]}} = {C_M}NaOH = 0,15M\\
pOH = - \log (0,15) = 0,82\\
pH = 14 - 0,82 = 13,18
\end{array}\)
