Boiling point of chloroform was raised by 0.323 K, when 0.5143 g of anthracene was dissolved in its 35 g. Molecular mass of anthracene is (Kb for CHCl3 = 3.9 K kg , mol-1)

Question

Boiling point of chloroform was raised by 0.323 K, when 0.5143 g of anthracene was dissolved in its 35 g. Molecular mass of anthracene is (Kb for CHCl3 = 3.9 K kg , mol-1) (A) 132.32 g/mol (B) 242.32 g/mol (C) 177.42 g/mol (D) 79.42 g/mol

Tardigrade Admin · Accepted Answer

Δ Tb=0.323 K, w=0.5143 g, W=35 g Kb (CHCl3)=3.9 Kg mol-1, M=? As, Δ Tb=(1000× Kb × w/M × W) ⇒ Molecular mass of anthracene (M) =(1000×3.9×0.5143/35×0.323) =177.42 g / mol

Q. Boiling point of chloroform was raised by $0.323 K$ , when $0.5143 g$ of anthracene was dissolved in its $35 g$ . Molecular mass of anthracene is $(K_{b}$ for $C H C l_{3} = 3.9 K k g, m o l^{- 1})$

$132.32 g / m o l$

$242.32 g / m o l$

$177.42 g / m o l$

$79.42 g / m o l$

$Δ T_{b} = 0.323 K$ , $w = 0.5143 g, W = 35 g$
$K_{b} (C H C l_{3}) = 3.9 K g m o l^{- 1}, M =$ ?
As, $Δ T_{b} = \frac{1000 \times K _{b} \times w}{M \times W}$
$\Rightarrow$ Molecular mass of anthracene $(M)$
$= \frac{1000 \times 3.9 \times 0.5143}{35 \times 0.323}$
$= 177.42 g / m o l$

Q. Boiling point of chloroform was raised by 0.323K, when 0.5143g of anthracene was dissolved in its 35g. Molecular mass of anthracene is (Kb​ for CHCl3​=3.9Kkg,mol−1)

132.32g/mol

242.32g/mol

177.42g/mol

79.42g/mol