Given the following thermochemical equation:

Question

NO2 (g) + O2 (g) → NO (g) + O3 (g)
ΔH = - 212 kJ

Which has more enthalpy, the reactants
NO2 (g) + O2 (g), or the products NO(g) + O3 (g) ?

The reactants have more enthalpy.

The products have more enthalpy.

The reactants and products have exactly equal enthalpy values.

This cannot be determined with the given information

Answer 1

Well look at the value given

a negative enthalpy means that energy was absorbed while a positive enthalpy means that energy was released

take a look at Hess' law

Enthalpy of products - Enthalpy of reactants = -212 kJ

If it's negative then that means the products are at a higher energy state (higher enthalpy) than the reactants