Answer to Question #141244 in Inorganic Chemistry for cindyann

Question

If 10.45 g of aluminum are reacted with 66.55 g of copper (II) sulphate, aluminum sulphate and copper are formed.
a.Which reactant is in excess?
b. Calculate the mass of copper formed.

Answer 1

Balanced reaction equation:

2Al + 3CuSO₄ = 3Cu + Al₂(SO₄)₃

Molar weight of Al: 26.98 g/mol

Quantity of Al: 10.45 g / 26.98 g/mol = 0.387 mol

Molar weight of CuSO₄: 159.61 g/mol

Quantity of CuSO₄: 66.55 / 159.61 g/mol = 0.417 mol

According to balanced equation, the ratio of reactants is 2 : 3.

So, aluminium is in excess.

Mass of copper must be calculated from quantity of copper sulfate:

Quantity of Cu (is the same as copper sulfate): 0.417 mol

Molar weight of Cu: 63.55 g/mol

Mass of Cu: 0.417 mol * 63.55 g/mol = 26.5 g

Answer: a) aluminium; b) 26.5 g