Question

Determine the theoretical yield of H2S (in moles) if 4.0 mol Al2S3 and 4.0 mol H2O.

Answer 1

the equation AL2S3(S)+6H2O(L)-2AL(OH)3(S)+3H2S(G)

Answer 2

Al2S3 + 6 H2O → 2 Al(OH)3 + 3 H2S

4 mol Al2S3 would react completely with 4 x 6 = 24 mol H2O, but there is not that much H2O present, so H2O is the limiting reactant.

(4 mol H2O) x (3/6) = 2 mol H2S