Identify the limiting reactant and excess reactant if 40g of copper is added to a solution with 300 g of silver nitrate.

Question

Need help answering the 3 questions!!!

*Also determine the mass of the silver metal that could be formed  as a result of the reaction and determine the mass of the excess reactant that would remain when the reaction is complete. 

Answer 1

The equation is:  Cu + 2AgNO₃ --> Cu(NO₃)₂ + 2Ag

 

The molecular weight of Cu is 63.55.  So 40 g is 0.63 moles

 

The molecular weight of AgNO₃ is 107.87 + 14.01 + 3*16 = 169.88.  So 300 g is 1.77 moles

 

So Cu is the limiting reactant.

 

.63 moles of Cu will result in 1.26 moles of Ag, which has a mass of 1.26 * 107.87 = 135.92 g of silver

 

1.26 moles of AgNO₃ will be used.  We started with 1.77 moles, so there will be .51 moles left.  Since the molecular weight is 107.87, the mass of excess reactant will be .51 * 107.87 = 55.01 g.

 

I THINK that's right!