Question

Molecular weight of PbCl2 = 278 g/mole Mass of beaker + PbCl2 = 62.19 g Mass of beaker = 57.77 g Mass of PbCl2 per 100 mL = g Moles PbCl2 per 100 mL = [Pb-2] based upon this investigation = M [Cl-] based upon this investigation = M

Answer 1

PbCl2--->Pb2+ + 2Cl-

The mass of PbCl2 is =mass of the beaker+Pbcl2 minus mass of the beaker
that is 62.19-57.77g= 4.42grams

moles of PbCl2= 4.42g/278g/m0l = 0.0159moles

concentration of (Pb2+)
since mole ratio of PbCl2 to Pb2+ is 1:1 therefore the moles of Pb2+ is also 0.0159moles
concentration =0.0159/100 x1000=0.159M

concentration of CI- is two time that of Pb2+ from the equation above therefore concentration of Cl- = 0.159 x2 =0.318M