Some Basic Concepts Of Chemistry Question 29
Question: Dissolving 120 g of a compound of mol. wt. 60 in 1000 g of water gave a solution of density 1.12 g/mL. The molarity of the solution is:
Options:
A) $ 1.00 M $
B) $ 2.00M $
C) $ 2.50M $
D) $ 4.00M $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] Given mass of solute (w) = 120 g mass of solvent (w) = 1000 g Mol. mass of solute = 60 g density of solution = 1.12 g/ mL From the given data, Mass of solution $ ~=1000+120=1120g $
$ \because d=\frac{Mol.mass}{V}or,V=\frac{Mol.mass}{d} $ Volume of solution $ ~V=\frac{1120}{1.12}=1000mL $ or = 1 litre Now molarity $ ( M )=\frac{W}{Mol.mass\times V(lit)} $
$ =\frac{120}{60\times 1}=2M $
