A) 0.70
B) 0.30
C) 0.125
D) 0.07
Correct Answer: A
Solution :
According to Raoults law, Relative lowering of vapour pressure = mole fraction of solute \[({{X}_{B}})=0.0125\] \[\because \] \[{{X}_{B}}=\frac{m\cdot {{M}_{A}}}{10000+m\cdot {{M}_{A}}}\] \[\therefore \] \[0.0125=\frac{m\times 18}{1000+m\times 18}\] \[12.5+0.225m=18m\] \[17.775m=12.5\] \[m=\frac{12.5}{17.775}=0.70\]
You need to login to perform this action.
You will be redirected in
3 sec
