Question

If we were to add a piece of solid Cu to an aqueous solution of silver (1) nitrate, the Silver would be replaced in a single replacement reaction forming aqueous copper (11) nitrate and solid silver. How much silver is produced if 15.00 grams of Cu is added to the solution of ecxess silver nitrate.

Answer 1

Solution:

The balanced chemical equation:

Cu(s) + 2AgNO₃(aq) → Cu(NO₃)₂(aq) + 2Ag(s)

According to the equation above: n(Cu) = n(Ag)/2

Moles of Cu = Mass of Cu / Molar mass of Cu

The molar mass of Cu is 63.546 g mol^-1.

Hence,

Moles of Cu = 15.00 g / 63.546 g mol^-1 = 0.236 mol

n(Cu) = 0.236 mol

n(Ag) = 2 × n(Cu) = 2 × 0.236 mol = 0.472 mol

Mass of Ag = Moles of Ag × Molar mass of Ag

The molar mass of Ag is 107.868 g mol^-1.

Hence,

Mass of Ag = 0.472 mol × 107.868 g mol^-1 = 50.9137 g = 50.9 g

Mass of Ag = 50.9 g

OR (short form solution):

(15.00 g Cu) × (1 mol Cu / 63.546 g Cu) × (2 mol Ag/1 mol Cu) × (107.868 g Ag / 1 mol Ag) = 50.9 g Ag

Answer: 50.9 grams of silver (Ag) is produced.