Question

200 ml of aqueous solution containing 8g of koh is mixed with 200 ml of decimolar koh solution what is the molatity of the final solution

Answer 1

Dear Student,

$$\begin{gathered} \mathrm{Molarity}\mathrm{of}\mathrm{resulting}\mathrm{mixture}\mathrm{solution}\mathrm{is}\mathrm{given}\mathrm{by} \\ \mathrm{M}=\frac{{\mathrm{M}}_1{\mathrm{V}}_1+{\mathrm{M}}_2{\mathrm{V}}_2}{{\mathrm{V}}_1+{\mathrm{V}}_2} \\ {\mathrm{M}}_1=\frac{8}{56}\times \frac{1000}{200}=0.714\mathrm{M} \\ {\mathrm{M}}_2=\frac{1}{10}=0.1\mathrm{M} \\ {\mathrm{V}}_1=200\mathrm{ml}=0.2\mathrm{L} \\ {\mathrm{V}}_2=200\mathrm{ml}=0.2\mathrm{L} \\ \mathrm{M}=\frac{0.714\times 0.2+0.1\times 0.2}{0.2+0.2}=\frac{0.1428+0.02}{0.4}=0.407\mathrm{M} \end{gathered}$$