Question

What is the maximum amount of copper that could be converted to Cu2+ ions by the concentrated nitric acid you used in part A of the experiment? The molarity of concentrated nitric acid is 16 M HNO3.

Cu(s) + 4HNO₃ --->Cu(NO₃)₂ + 2NO₂ + 2H₂O

Mass of penny : 3.130g

mass of Cu recovered: 2.974g

Answer 1

Molarity of HNO₃ = (Mass of penny/ Molar mass of HNO₃)/( Volume of solutions in liters)

Molar mass of  HNO₃ = 63.01 g/ mol and Molarity of HNO₃ = 16 M and Mass of Penny = 3.130g

Mass of Cu recovered = 2.974g

Therefore , Volume of solution = (3.130g / 63.01g/ mol)/ 16 M = 0.0496 mol / 16 M = 0.0031 L

Now Again Molarity of HNO₃ = (Mass of Cu recovered/ Molar mass of Cu²⁺ maximum amount )/( Volume of solutions in liters)

16 M = (2.974g/Molar mass of Cu²⁺ maximum amount )/0.0031 L

Molar mass of Cu²⁺ maximum amount = 2.974/(0.0031*16) = 2.974/0.0496 = 59.95 g/ mol

Maximum amount of Copper that would be converted to Cu²⁺ in Concentrated HNO₃ = 59.95 g/mol