[INeedSerotonin]

Hello

I have to write down the reaction that is happening between CuO + C. How can I know it?

I know that the answer is Cu + CO₂, but why couldn't it be Cu₂O + CO, for example?

Thank you

[Borek]

Actually you are perfectly right that predicting final result is quite difficult without knowing relative amounts of substances involved, and definitely - in some circumstances - CO can be a product.

But judging from your other questions you are just beginning to learn chemistry, so you can safely assume the reaction goes to the simplest, most obvious products (and to completion). Besides, the image says there are reddish metallic granules present and white precipitate is observed, so the outcome is rather obvious.

[INeedSerotonin]

Thank you! 

[AWK]

At temperatures below 800 C, there is also a reaction: 2CO = CO₂ + C