How would you describe the following chemical reaction? 2CO(g)+O2(g) --> 2CO2(g) + energy

(a)exothermic
(b) endothermic

B

Explanation:

The normal way to express an energy reaction is to put the energy on the left. Then you can make a rule.

If the energy on the left is plus then the reactants require energy. The reaction is endothermic -- energy is taken from the environment.If the energy is minus when it is on the left. then the reactants give up energy. The reaction is exothermic and energy is given to the environment.

2CO(g)+O2(g) - energy --> 2CO2(g)

Exothermic

Exothermic,  physical change after it is already baked