Elevation in boiling point for 1 . 5 molal solution of glucose in water is 4   K . The depression in…

Elevation in boiling point $∆{\mathrm{T}}_{\mathrm{b}}={\mathrm{ik}}_{\mathrm{b}}{\mathrm{m}}_1$

Depression in freezing point $∆{\mathrm{T}}_{\mathrm{f}}={\mathrm{ik}}_{\mathrm{f}}{\mathrm{m}}_2$

$4={\mathrm{ik}}_{\mathrm{b}}\left(1.5\right)$

$4={\mathrm{ik}}_{\mathrm{f}}\left(4.5\right)$

Dividing both:

$\frac{{\mathrm{k}}_{\mathrm{b}}}{{\mathrm{k}}_{\mathrm{f}}}=\frac{3}{1}$

Hence, The ratio of molal elevation constant to molal depression constant is  3:1