On dissolving 2.34g of non-electrolyte solute in 40g of benzene, the boiling point of solution was higher than benzene by 0.81K. Kb value for benzene is 2.53 K `kgmol^(-1)` .Calculate the molar mass of solute. [Molar mass of benzene is 78 `gmol^(-1)`]

Explanation

Data: Mass of solute=`W_(2)=2.34g`, mass of solvent benzene`=W_(1)=40g`
`K_(b)=2.53K.kg" "mol^(-1)`, Elevation in boiling point=0.81K
Molar mass of solute=`M_(2)=?`
Formula `M_(2)=(W_(2))/(W_(1))xx(1000)/(DeltaT_(b))`
Substitution: `M_(2)=2.53xx(2.34)/(40)=(1000)/(0.81)`.
Answer `M_(2)=182.72g" "mol^(-1)`.