Em tham khảo nha:
\(\begin{array}{l}
a)\\
{\rm{[}}N{a^ + }{\rm{]}} = {\rm{[}}O{H^ - }{\rm{]}} = {C_M}NaOH = 2M\\
b)\\
{\rm{[}}{H^ + }{\rm{]}} = {\rm{[}}C{l^ - }{\rm{]}} = {C_M}HCl = 0,5M\\
c)\\
{\rm{[}}{H^ + }{\rm{]}} = 2{C_M}{H_2}S{O_4} = 0,2 \times 2 = 0,4M\\
{\rm{[}}S{O_4}^{2 - }{\rm{]}} = {C_M}{H_2}S{O_4} = 0,2M\\
d)\\
{\rm{[}}F{e^{3 + }}{\rm{]}} = {C_M}FeC{l_3} = 0,3M\\
{\rm{[}}C{l^ - }{\rm{]}} = 3{C_M}FeC{l_3} = 0,3 \times 3 = 0,9M\\
e)\\
{n_{MgS{O_4}}} = \dfrac{{12}}{{120}} = 0,1\,mol\\
{n_{M{g^{2 + }}}} = {n_{S{O_4}^{2 - }}} = 0,1\,mol\\
{\rm{[}}M{g^{2 + }}{\rm{]}} = {\rm{[}}S{O_4}^{2 - }{\rm{]}} = \dfrac{{0,1}}{{0,2}} = 0,5M\\
f)\\
{n_{A{l_2}{{(S{O_4})}_3}}} = \dfrac{{34,2}}{{342}} = 0,1\,mol\\
{n_{A{l^{3 + }}}} = 2{n_{A{l_2}{{(S{O_4})}_3}}} = 0,2\,mol\\
{n_{S{O_4}^{2 - }}} = 3{n_{A{l_2}{{(S{O_4})}_3}}} = 0,3\,mol\\
{\rm{[}}A{l^{3 + }}{\rm{]}} = \frac{{0,2}}{{0,2}} = 1M\\
{\rm{[}}S{O_4}^{2 - }{\rm{]}} = \dfrac{{0,3}}{{0,2}} = 1,5M
\end{array}\)
