How many grams of the excess reactant remain assuming the reaction goes to completion and that you start with 15.5 g of Na2S and 12.1 g CuSO4?
Reaction: Na2S + CuSO4 ? Na2SO4 + CuS
A) 0.05
B) 15.45
C) 9.58
D) 5.92
E) not enough information
Answer: C