Question 10

A 75.0 - mL sample of 1.54*10-2 M Na2SO4 (aq) is added to 75.0 mL of 1.22*10-2 M Ca (NO3) 2 (aq).

Part A

What percentage of the Ca2 + remains unprecipitated?

Express your answer using two significant figures.

The reaction that should be followed is

Na2SO4 + C a (NO3) 2 - - > CaSO4 + 2NaNO3

first calculate the limiting reactant

mol Na2SO4 = 0.075 L (1.54*10-2 mol / L) = 1.155x10-3 mol

mol Ca (NO3) 2 = 0.075 L (1.22*10-2 mol / L) = 9.15x10-4 mol

so the limiting reactant is the Ca (NO3) 2

so all of the Ca2 + will be precipitated, percentage unprecipitated = 0.00 %