Question

Heyya!! Chemists✌✌
The mole fraction of benzene in a solution in toluene is 0.50. Calculate the weight percent of benzene in the solution.​

Answer 1

Answer :

• Weight percent of benzene in the solution = 45.9%.

Step-by-step explanation :

Given that,

• Mole fraction of benzene in the solution = 0.50.

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Suppose the weight percent of benzene in the solution = x. This means that in 100 g solution,

☛ Mass of benzene = x g

☛ Mass of toluene = (100 - x) g

☛ Mol. mass of benzene ($\bold{C_6H_6}$) = 78

☛ Mol. mass of toluene ($\bold{C_6H_5CH_3}$) = 92

$\rule{200}3$

∴ $\bold{\dfrac{n_B}{(n_B+n_T)}=0.50}$

$\implies\bold{\dfrac{w_B/78}{w_B/78+w_T/92}=0.50}$

$\implies\bold{\dfrac{x/78}{x/78+(100-x)/92}=0.50}$

$\implies\bold{\dfrac{x}{\cancel{78}}\times{}\dfrac{\cancel{78}\times{}92}{92x+78(100-x)}=0.50}$

$\implies\bold{92x=46x+3900-39x}$

$\implies\bold{85x=3900}$

$\implies\bold{x=45.9\%}$

∴ Weight percent of benzene in the solution is 45.9%.