Solutions Question 348
Question: 0.5 molal aqueous solution of a weak acid (HX) is 20% ionised. If $ K_{f} $ for water is $ 1.86Kkgmo{l^{-1}} $ , the
Options:
A) 0.56K
B) 1.12K
C) $ -0.56K $
D) $ -1.12K $
Show Answer
Answer:
Correct Answer: B
Solution:
As $ \Delta T_{f}=K_{f}.m $ For, Total no. of moles $ =1-0.20+0.20+0.20 $
$ =1+0.20=1.2 $
$ \therefore \Delta T_{f}=1.2\times 1.86\times 0.5=1.1160\approx 1.12K $
