0.500 grams of calcium nitrate were
added to a solution of unknown
sodium salt where the salt is known
to be in excess.
The potential precipitation reactions
are shown below.
Reaction I:
Ca(NO3)2 + Na2SO4 → CaSO4 + 2NaNO3
Reaction II:
Ca(NO3)2 + Na2CO3 → CaCO3 + 2NaNO3
Reaction III:
Ca(NO3)2 + NaOH
→>
Ca(OH)2 + NaNO3


What is the theoretical mass of CaSO4 formed from 0.500 grams of calcium nitrate and excess sodium sulfate?
0.305 g CaSO4
0.00305 g CaSO4
0.415 g CaSO4