Question

A scientist is studying a previously unknown chemical reaction. She concludes that it is exothermic. What must the scientist have observed?
The reaction released heat.
The reaction formed a gas.
The reaction sped up when a catalyst was added.
The reaction caused the container to get cold.

Answer 1

I think the correct answer from the choices listed above is the first option. She concluded that the reaction is an exothermic one because the reaction released heat. Exothermic is when heat goes out of the system. The opposite is referred to as an endothermic reaction.

Answer 2

A. The reaction released heat.