Question

Classify each of the following processes as exothermic or endothermic and indicate the sign of ΔH.

butane gas burning in a lighter

the reaction that occurs in a chemical cold pack often used to ice athletic injuries

the burning of wax in a candle

Answer 1

1)  

butane gas burning in a lighter ------------------------> exothermic and ΔH is negative

2)

the reaction that occurs in a chemical cold pack often used to ice athletic injuries --------> endothermic, ΔH is positive

3)

the burning of wax in a candle ------------------------> exothermic and ΔH is negative

explanation :

burning reaction means it is combustion reaction and all combustion reactions are exothermic in nature.

for exothermic reactions deltaH is negative and fro endothermic reaction deltaH is positive