Question

Cu + O2 --Cu2O

Answer 1

Answer:

a. 4Cu + O₂ → 2Cu₂O

b. 266g Cu

c. 102g Cu₂O

Explanation:

Based on the balanced reaction:

a. 4Cu + O₂ → 2Cu₂O

4 moles of Cu reacts per mole of oxygen to produce 2 moles of Cu₂O.

b. To solve this question we need to find the moles of Cu₂O. With these moles and the balanced reaction we can find the moles of Cu and its mass:

Moles Cu₂O -Molar mass: 143.09g/mol-

300g Cu₂O * (1mol / 143.09g) = 2.097 moles Cu₂O

Moles Cu:

2.097 moles Cu₂O * (4mol Cu / 2mol Cu₂O) 4.193 moles Cu

Mass Cu - Molar mass: 63.546g/mol-

4.193 moles Cu * (63.546g / mol) = 266g Cu

c. In the same way, using PV = nRT we can find the moles of Oxygen. With the moles of oxygen we can find the moles of Cu₂O and its mass:

n = PV / RT

P = 1atm at STP, V = 8.0L, R = 0.082atmL/molK, T = 273.15K at STP:

n = 1atm*8.0L / 0.082atmL/molK*273.15K

n = 0.357 moles O₂

Moles Cu₂O:

0.357 moles O₂ * (2mol Cu₂O / 1mol O₂) = 0.714 moles Cu₂O

Mass Cu₂O -Molar mass: 143.09g/mol-

0.714 moles Cu₂O * (143.09g/mol) =

102g Cu₂O