Question

What is the molarity of ZnCl2(aq) that forms when 20.0 g of zinc completely reacts with CuCl2(aq) according to the following reaction? (Assume a final volume of 195 mL .)
Zn(s)+CuCl2(aq)→ZnCl2(aq)+Cu(s)

Answer 1

Zn(s)+CuCl2(aq)→ZnCl2(aq)+Cu(s)

no of moles of Zn   = W/G.A.Wt

                                = 20/65.4 = 0.306 moles

1 moles of Zn react with CuCl2 to gives 1 moles of ZnCl2

0.306 moles of Zn react with CuCl2 to gives 0.306 moles of ZnCl2

molarity of ZnCl2   = no of moles/volume in L

                               = 0.306/0.195    = 1.57 M >>>>>answer