Question

A solution contain substances A and B in H,O(solvent). The mole fraction of 'A' is 0.05 andmolarity of 'B' is 7 M. The solution has density1.14 gm/ml. Calculate "molarity of A".[Molecular weight of A = 10 gm/mol; molecularweight of B = 30 gm/mol]​

Answer 1

Answer:

The answer is 0.88 M

Explanation:

Mole fraction of A, Xa = nA/nT= 0.05 = 5/100

It means 5 moles of A are present in 100 molesw of  solution.

Thus

nA  + nB + H2O = 100

Let's suppose water is 100 ml  

So no of moles of water is nH2O= 100/18 = 55.55 mol

nB = 100 - 55.55 - 5 = 39.45 mol  

Now find the volume of solution.

The volume of solution = Moles of B / 7 = 39.45/7  

                                   = 5.63 L

Molarity of A = 5/5.63 = 0.88 M