question_answer

The elevation in boiling point of a solution of 13.44 g of \[CuC{{l}_{2}}\] in 1 kg of water using the following information will be (Molecular weight of \[CuC{{l}_{2}}=134.4g\] and\[{{K}_{b}}=0.52\,Kkg\,mo{{l}^{-1}}\])

A) 0.16                 

B) 0.05 

C) 0.1                   

D) 0.2

Correct Answer: A

Solution :

[a] (i)  \[i=\frac{No.\text{ }of\text{ }particles\text{ }after\text{ }ionisation}{No.\text{ }of\text{ }particles\text{ }before\text{ }ionisation}\] (ii) \[\Delta {{T}_{b}}=i\times {{K}_{b}}\times m\] \[i=\frac{1+2\alpha }{1},=1+2\alpha \] Assuming 100% ionization So, \[i=1+2=3\] \[\Delta {{T}_{b}}=3\times 0.52\times 0.1=0.156\approx 0.16\] \[\left( m=\frac{13.44}{134.4}=0.1 \right)\]