QJEEM17Ch3a8f: JEE Main 2017 Chemistry - Class 12 JEEM17Ch3a8f Solution: A solution is prepared by mixing 8.5 g of CH 2 Cl 2 and 11.95 g …

Mole fractions can be calculated as

${n_{C{H_2}C{l_2}}} = {{8.5} \over {8.5}} = 0.1$ and ${n_{CHC{l_3}}} = {{11.9} \over {119.5}} = 0.1$

We know that

${p_{total}} = p_{C{H_2}C{l_2}}^o \times \,{x_{C{H_2}C{l_2}}} + p_{CHC{l_3}}^o \times \,{x_{CHC{l_3}}}$

$= 415 \times 0.10 + 200 \times 0.1 = 61.5$

Mole fraction of CHCl₃ in vapour form can be calculated as

${p_{total}} = p_{CHC{l_3}}^o \times \,{x_{CHC{l_3}}}$

$61.5 = 200 \times \,{x_{CHC{l_3}}}$

${x_{CHC{l_3}}} = {{61.5} \over {200}} = 0.3075$