The chemical reaction is given as:
Al2S3(s) + 6 H2O(l) → 2 Al(OH)3(s) + 3 H2S(g)
We are given the amount of the reactants to be used for the reaction. We need to convert these masses to determine the limiting reactant to use for the calculations.
2.00 g Al2S3 ( 1 mol / 150.17 g ) = 0.0134 mol Al2S3
2.00 g H2O ( 1 mol / 18.02 g ) = 0.1110 mol H2O
Therefore, the limiting reactant is Al2S3 since it is what is consumed completely in the reaction. Hope this answers the question. Have a nice day.