Answer:
72.4%
Explanation:
Step 1: Write the balanced equation
2 Cu + S ⇒ Cu₂S
Step 2: Calculate the theoretical yield, in moles, from 0.0970 moles of Cu
The molar ratio of Cu to Cu₂S is 2:1.
0.0970 mol Cu × 1 mol Cu₂S/2 mol Cu = 0.0485 mol Cu₂S
Step 3, Convert the theoretical yield to mass
The molar mass of Cu₂S is 159.16 g/mol.
0.0485 mol × 159.16 g/mol = 7.72 g
Step 4: Calculate the percent yield
We will use the following expression.
%yield = experimental yield/theoretical yield × 100%
%yield = 5.59 g/7.72 g × 100% = 72.4%
