J.R. S. answered 11/11/21
Ph.D. University Professor with 10+ years Tutoring Experience
2KCl(aq) + Pb2+(aq) ==> PbCl2(s) + 2K+(aq) ... balanced equation
mols Pb2+ = 14.0 ml Pb(NO3)2 x 1L/1000 ml x 0.350 mol/L x 1 mol Pb2+/mol Pb(NO3)2 = 0.00490 mols Pb2+
mols KCl needed = 0.00490 mol Pb2+ + 2 mol KCl/mol Pb2+ = 0.00980 mols KCl needed