Exothermic Reaction

i was looking at the ingredients in my jar of penut butter, i looked  one of the ingredients up, this is what it says(Copper sulfate is a commonly included chemical in children’s chemistry sets and is often used to grow crystals in schools and in copper plating experiments. Because of its toxicity, it is not recommended for small children. Copper sulfate is often used to demonstrate an exothermic reaction,Copper sulfate was also used in the past as an emetic.[16] It is now considered too toxic for this use.[17] It is still listed as an antidote in the Continue Reading