Solutions Question 94
Question: The elevation in boiling point of a solution of 13.44g of CuCl2 in 1kg of water using the following information will be (Molecular weight of CuCl2 = 134.4 and Kb = 0.52 K molal-1) [IIT 2005]
Options:
A) 0.16
B) 0.05
C) 0.1
D) 0.2
Show Answer
Answer:
Correct Answer: A
Solution:
DTb = i.Kb.m CuCl2 $ \xrightarrow{{}} $ Cu2+ + 2Cl- 1 0 0 (1-a) a 2a i = 1 + 2a Assuming 100% ionization So, i = 3 DTb = 3 ´ 0.52 ´ 0.1 = 0.156 » 0.16