An aqueous solution freezes at `-0.186^@C (K_f=1.86 ,K_b, =0.512^@).` What is the elevation in boiling point?

Options

A. `0.186`
B. `0.512`
C. `(0.512)/(1.86)`
D. `0.0512`

Answer

D

Explanation

`Delta T_(b)= K_(b) xx` Molality
`Delta T_(f)= K_(f) xx` Molality
`therefore (Delta T_(b))/(Delta T_(f))= (K_(b))/(K_(f)) rArr Delta T_(b)= (Delta T_(f) xx K_(b))/(K_(f))= (0.186 xx 0.512)/(1.6)= 0.0512`