What is the theoretical yield in grams of CuS for the following reaction given that you start with 15.5 g of Na2S and 12.1 g CuSO4?
Reaction: Na2S + CuSO4 ? Na2SO4 + CuS
A) 0.0758
B) 0.198
C) 18.93
D) 7.25
E) not enough information
Answer: D