Answer:
when the energy is added on the left side of reaction it means reaction is endothermic
or
when ΔH is positive it means reaction is endothermic.
Explanation:
Endothermic reactions:
In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.
For example:
C + H₂O → CO + H₂
ΔH = +131 kj/mol
it can be written as,
C + H₂O + 131 kj/mol → CO + H₂
when the energy is added on the left side of reaction it means reaction is endothermic
or
when ΔH is positive it means reaction is endothermic.
Exothermic reaction:
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
