Question

1 molal aqueous solution of an electrolyte $A_2{B}_3$ is 60% ionised . The boiling point of the solution at 1 atm in K is ( Rounded -off to the nearest integer ) $[K_{b}for\left(H_{2}O\right)=0.53KKgmo{l}^{-1}]$
(JEE MAIN 2021)

Answer 1

( Assuming A - cation , B - anion ) $A_2{B}_3\to 2A^{3+}+3B^{2-}1-0.62\times 0.63\times 0.6$ $\therefore \text{van't Hoff factor}=1-0.6+1.2+1.8=3.4$ $\Delta T_b=i\times K_b\times m$ $\Delta T_b=3.4\times 0.52\times 1=1.768$ $T_b-373=1.768$ $T_b=374.77\approx 375\left(\text{Nearest integer}\right)$