52.1 mL of aqueous 0.255 M Pb(NO3)2 is mixed with 38.5 mL of 0.415 M NaCl. The equation for the precipitate reaction is: Pb(NO3)2 (aq) 2 NaCl (aq) --> PbCl2 (s) 2 NaNO3 (aq) The concentration of Pb2 ion in the solution is M after the reaction is complete.

0.0585 M

Explanation:

First we calculate the inital number of moles of each reagent, using the given volumes and concentrations:

Then we calculate how many Pb(NO₃)₂ moles reacted with 16.0 mmoles of NaCl, using the stoichiometric coefficients of the reaction:

Now we calculate the remaining number of Pb(NO₃)₂ moles after the reaction:

Finally we divide the number of moles by the final volume to calculate the concentration: