Solutions Question 137
Question: If 5.85 gms of $ NaCl $ are dissolved in 90 gms of water, the mole fraction of $ NaCl $ is [CMC Vellore 1991; MP PMT 1994; AFMC 1998]
Options:
A) 0.1
B) 0.2
C) 0.3
D) 0.01
E) 0.0196
Show Answer
Answer:
Correct Answer: E
Solution:
5.85 g NaCl = $ \frac{5.85}{58.5},mole=0.1mol $ 90 g $ H_2O=\frac{90}{18},moles=5moles $ mole fraction of NaCl = $ \frac{0.1}{5+0.1}\approx 0.0196 $ .
