Q. The van’t Hoff factor of $BaCl_{2}$ at 0.01 M concentration is 1.98. The percentage of dissociation of $BaCl_{2}$ at this concentration is
A) 49
B) 69
C) 89
D) 98
Explanation
(a)
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ BaCl_{2}\ \ \ \ \rightleftharpoons \ \ \ \ \ Ba^{2 +}\ \ \ \ + \ \ \ \ 2Cl^{-}$
Initial 0.01 M
At equilibrium (0.01-x) M xM 2xM
i=$\frac{(0.01 - x) + x + 2x}{0.01}$
= $\frac{0.01 + 2x}{0.01} = 1.98$
x=0.0049
%$\ \alpha = \frac{x}{0.01} \times 100 = \frac{0.0049 \times 100}{0.01} = 49\%$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.