**Q4 . A solution contain substances A and B in H**_{2}O (solvent). The mole fraction of A is 0.05 and the molarity of B is 7M. The solution has density 1.14 gm/ml. Calculate molarity of A.

[Molecular weight of A = 10 gm/mol; molecular weight of B = 30 gm/mol]

**Q5 . Assuming complete precipitation of AgCl, calculate the sum of the molar concentration of all the ions if 2 litre of 2 M Ag**_{2}SO_{4} is mixed with 4 litre of 1M NaCl solution is [Ag_{2}SO_{4} + 2NaCl --> 2AgCl + Na_{2}SO_{4}]