Question

In the reaction K2CrO4 (aq) + PbCl2 (aq) 2KCl (aq) + PbCrO4(s), how many grams of PbCrO4 will precipitate out from the reaction between 25.0 milliliters of 3.0 M K2CrO4 in an excess of PbCl2?

Answer 1

Reaction equation:
K₂CrO₄(aq) + PbCl₂(aq) → 2KCl(aq) + PbCrO₄(s)

Concentration = moles / Liter
moles(K₂CrO₄) = 3 x 0.025
= 0.075

By the equation, we see that the molar ratio of
K₂CrO₄ : PbCrO₄ is
1 : 1
moles(PbCrO₄) = 0.075

mass = moles x Mr
mass = 0.075 x (207 + 52 + 16 x 4)

mass = 24.2 grams