What mass of lead chloride would result if a 21.5mL volume of lead nitrate at 0.0806molL1 concentration were mixed with a 18.00mL volume of potassium chloride at 0.683molL1 concentration?

1 Answer
Jun 20, 2017

Under a 2g mass................

Explanation:

We need (i) a stoichiometric equation.....

Pb(NO3)2(aq)+2KCl(aq)PbCl2(s)+2KNO3(aq)

Lead chloride is one of the few water-insoluble halides. It crashes out of water solution with alacrity.

And (ii) we need equivalent quantities of each reagent......

Moles of lead nitrate=21.5×103L×0.806molL1=0.0173mol

Moles of KCl=18.00×103L×0.683molL1=0.0123mol.

And thus (clearly) chloride anion is the limiting reagent. Stoichiometry predicts that half an equiv of plumbous chloride will precipitate.

Mass of PbCl2 = 0.0123mol2×278.10gmol1

=1.71g

It is unusual that the chloride ion is in stoichiometric deficiency in that you would think we want to salt out the lead content......