Final answer:
The theoretical yield of copper sulfide (CuS) expected from reacting 200g of Cu with 150g of S is 301.17g, with copper being the limiting reactant and the reaction having a 1:1 stoichiometry.
Step-by-step explanation:
To determine the amount of CuS expected from reacting 200g of Cu with 150 g of S, one must first identify the limiting reactant. The molar mass of copper (Cu) is 63.55 g/mol, and sulfur (S) has a molar mass of approximately 32.07 g/mol. By dividing the mass of each reactant by its respective molar mass, we can find the number of moles of each reactant.
For copper: 200 g Cu ÷ 63.55 g/mol
= 3.15 mol Cu
For sulfur: 150 g S ÷ 32.07 g/mol
= 4.68 mol S
The reaction between copper and sulfur to form copper sulfide (CuS) is a 1:1 reaction (1 mole of Cu reacts with 1 mole of S to form 1 mole of CuS).
Therefore, sulfur is in excess, and copper is the limiting reactant.
The theoretical yield of CuS is the same as the number of moles of the limiting reactant, which is 3.15 mol of CuS.
Since 1 mol of CuS has a molar mass of approximately 95.61 g/mol (63.55 g/mol for Cu + 32.07 g/mol for S), the theoretical mass of CuS produced would be 3.15 mol × 95.61 g/mol = 301.17 g CuS.