Equilibrium Question 283
Question: A 0.004 M solution of $ Na_2SO_4 $ is isotonic with a 0.010 M solution of glucose at same temperature. The apparent degree of disociation of $ Na_2SO_4 $ is [IIT JEE Screening 2004]
Options:
A) 25%
B) 50%
C) 75%
D) 85%
Show Answer
Answer:
Correct Answer: C
Solution:
$ \underset{(0.004-x)}{\mathop{Na_2SO_4}}, $ ⇌ $ \underset{2x}{\mathop{2N{a^{+}}}},+\underset{x}{\mathop{SO_4^{2-}}}, $ Since both the solution are isotonic $ 0.004+2x=0.01 $
$ \therefore \ \ x=3\times {10^{-3}} $
$ \therefore \ \ $ Percent dissociation $ =\frac{3\times {10^{-3}}}{0.004}\times 100=75% $ .
