Question

if enthalpy is the heat for a reaction,it must have a sign as well as a magnitude.What sign should the enthalpy for an exothermic reaction have?Why?

Answer 1

We know that exothermic reactions give off heat. Therefore the sign of the enthalpy would be negative because we’re losing it.

You can think of it like this

Endothermic +h

Reactant(s) + h —> product(s)

Exothermic -h

Reactant(s) —> product(s) + h