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 " CHCl_3 = 3.9 K kg mol^(-1))`

Options

A. 132.32 g/mol
B. 242.32 g/mol
C. 177.42 g/mol
D. 79.42 g/mol

Answer

C

Explanation

`DeltaT_b = 0.323 K, w=0.5143 g, W = 35 g`
`K_b (CHCI3) = 3.9 K kg mol^(-1),m=? " As," Delta_b = (1000 xx K_bxxw)/(mxxW)`
`implies` Molecular mass of anthracene (m)
`=(1000xx3.9 xx 0.5143)/(35xx0.323) = 177.42`