Question

Is the reduction of copper from copper(ii) oxide by carbon exothermic or endothermic? what is the sign of the energy change?

Answer 1

Answer;

-Exothermic reaction;

-The sign of the energy change is negative (-)

Explanation;

2CuO(s) + C(s) --> 2Cu(s) + CO2(g)  

ΔH = ΣΔHf(products) - ΣΔHf(reactants)  

ΔH = -393.5kJ - 2(-155.2kJ) = -83.1 kJ  

The reaction is exothermic.

-An exothermic process or reaction releases heat, causing the temperature of the immediate surroundings to rise. An endothermic process absorbs heat and cools the surroundings.