How many grams of chromium are needed to react with an excess of #CuSO_4# to produce 16.2 g Cu?
Refer to the explanation for the process.
Start with a balanced equation.
Determine moles Cr from the given mass and the molar mass (51.996 g/mol).
Determine moles Cu by multiplying by the mole ratio between Cr and Cu from the balanced equation, with Cu in the numerator.
Determine mass Cu by multplying mol Cu by molar mass Cu (63.546 g/mol).
The steps can be combined into one equation:
Note: This is the mass of copper that can be produced in an excess of copper sulfate in a closed system, and assuming that there are no side reactions and that the reaction went to completion. So If this were an actual experiment that you performed, you would most likely get less copper.