Question

Find the molality, molarity mole fraction of 12% w/v solution (density =1.2g/ml).Molecular weight of solute is 40

Answer 1

Answer:

molality=3m

molarity=0.9M

mole fraction =0.0512

Explanation:

1) molality=no.of mole of solute /mass of salvent

12%w/v means 12gm solute in 100gm water

no. of mole of solute = 12/40

= 0.3

molarity = 0.3/100 ×1000

= 3 m

2) molarity=no. of mole of solute/ vol of sol.

vol of sol = 100/ 1.3

= 333.33ml

molarity = 0.3/333.33×100

= 0.9M

3) mole fraction of solute = nB/nA+nB

nA = 100/18

= 5.55

mole fraction = 0.3/0.3+5.55

= 0.0512