Question

Y g of non-volatile organic substance of molecular mass M is dissolved in 250 g benzene . Molal elevation constant of benzene is `K_(b)` . Elevation in its boiling point is given by :
A. `(M)/(K_(b)y)`
B. `(4K_(b)y)/(M)`
C. `(K_(b)y)/(4M)`
D. `(K_(b)y)/(M)`

Answer 1

Correct Answer - B
`Delta T = K_(b) xx (w_(B) xx 1000)/(m_(B) xx w_(A))`
`= K_(b) xx (y xx 1000)/(M xx 250) = (4 K_(b) y)/(M)`