Chemistry - Liquid Solution Question with Solution | TestHub

${{\text{(T}}_{\text{f}}\text{)}}_{\text{A}}\text{=}{{\text{(T}}_{\text{f}}\text{)}}_{\text{B}}$
$\Rightarrow {{\text{(ΔT}}_{\text{f}}\text{)}}_{\text{A}}\text{=}{{\text{(ΔT}}_{\text{f}}\text{)}}_{\text{B}}$
$\Rightarrow \text{i}\text{×}{\text{K}}_{\text{f}}\text{×}{\text{m}}_{\text{A}}\text{=}\text{i}\text{×}{\text{K}}_{\text{f}}\text{×}{\text{m}}_{\text{B}}$
$\Rightarrow {\text{m}}_{\text{A}}\text{=}{\text{m}}_{\text{B}}$
$\Rightarrow \frac{{\text{w}}_{\text{A}}}{{\text{M}}_{\text{A}}}\text{×}\frac{\text{1000}}{{\text{w}}_{\text{solvent}\text{(g)}}}\text{=}\frac{{\text{w}}_{\text{B}}}{{\text{M}}_{\text{B}}}\text{×}\frac{\text{1000}}{{\text{w}}_{\text{solvent}\text{(g)}}}$
$\Rightarrow \frac{\text{3}}{\text{60}}\text{×}\frac{\cancel{\text{1000}}}{\text{97}}\text{=}\frac{\text{9}}{{\text{M}}_{\text{B}}}\text{×}\frac{\cancel{\text{1000}}}{\text{91}}$
$\Rightarrow {\text{M}}_{\text{B}}=\frac{9\times 60\times 97}{3\times 91}$
$\therefore {\text{M}}_{\text{B}}=191.9\text{g/mol}$