Study the balanced chemical reaction.

Question

2Cu + O2 → 2CuO

There are 6.45 g of copper(II) oxide (CuO) produced. What amount of the product, in g, is copper?

5.15 g

8.07 g

3.23 g

1.60 g

Is it B?

Answer 1

B? Did you just guess?
How can there be more Cu than the total mass of CuO?
Where's your work?

using the mol wts,
Cu/CuO * 6.45 = 63.54/79.54 * 6.45 = 5.15 g