Question

What is the amount of CuO formed when 63.5 g of copper is heated strongly in air?

A) 63.5 g
B) 69.5 g
C) 73.5 g
D) 79.5 g

Answer 1

The amount of CuO formed when 63.5 g of copper is heated in air is found by calculating the moles of Cu, then using the stoichiometry from the balanced chemical equation, and finally finding the mass of CuO formed. The correct answer is 79.5 g of CuO.

Step-by-step explanation:

To determine the amount of CuO formed when 63.5 g of copper is heated in air, the following steps need to be taken:

1. Write the balanced chemical equation for the reaction: 2Cu + O2 → 2CuO.
2. Calculate the molar mass of copper (Cu), which is 63.55 g/mol.
3. Find out how many moles of copper are in 63.5 g by dividing the mass of copper by its molar mass: 63.5 g Cu ÷ 63.55 g/mol = 0.99921 mol Cu.
4. From the balanced equation, we know that 1 mole of Cu produces 1 mole of CuO.
5. Calculate the molar mass of CuO, which is Cu (63.55 g/mol) + O (16.00 g/mol) = 79.55 g/mol.
6. Find the mass of CuO formed by multiplying the moles of Cu by the molar mass of CuO: 0.99921 mol Cu × 79.55 g/mol = 79.5 g CuO.

Therefore, the correct answer is D) 79.5 g.