What compounds are produced when you heat CuO and sugar?
If there is enough copper oxide, all you obtain is metallic copper, $\ce{CO2}$ and water. This mixture ($\ce{CuO}$ + organic substance) was the standard way of analyzing any new organic substance in the $19$th century. The formula of the compound was derived from the weight of $\ce{CO2}$ and $\ce{H2O}$ collected. This is is still a standard question to be solved in high school chemistry courses all over the world.