Answer
a) Theoretical yield: $14.3\ g$
b) Percent yield: $88.3\%$
Work Step by Step
a) Number of moles of copper (II) sulfate:
$10.0\ g\div 159.61\ g/mol= 0.063\ mol$, the same as the compound.
Theoretical yield:
$0.063\ mol\times 227.73\ g/mol=14.3\ g$
b) Percent yield:
$12.6/14.3\times100\%=88.3\%$
