The document discusses the phase change of a system from liquid to solid. It explains that if heat is released during this process, it is exothermic, while if heat is absorbed, it is endothermic. Since changing from liquid to solid releases heat, the system experiences an exothermic reaction.

1. A system experiences a phase change from liquid to solid. Is this exothermic or endothermic?
OEndothermic O Exothermic More information is needed
Solution
If heat is released then the system is exothermic
If heat is absorbed then the system is endothermic
when liquid is changed to solid heat is released,therefore the system experiences exothermic
reaction