Question

Q2. A solution of 2.5 g of a non-
volatile solid in 100 g benzene is
boiled at 0.42°C higher than the
boiling point of pure benzene.
Calculate the molecular mass of the
substance. Molal elevation constant
of benzene is 2.67 K.kg.mol-1*​

Answer 1

Answer:

158.92 g/mol

Explanation:

W2 = wt. of solute = 2.5g

W1 = wt.of solvent= 100g

M2 = molar mass of solute = ?

∆Tb = 0.42°C

kb= 2.67KKg/mol

using ∆Tb =( Kb × W2×1000)/(M2×W1)

solving M2 = 158.92 g/mol