Answer:
1.The reaction that opposes the change
Step-by-step explanation:
Consider the reaction;
A + B ⇄ C + D
If a constraint such as a change in temperature, pressure or volume is imposed on this chemical system in dynamic equilibrium, the equilibrium position will shift so as to annul the constraint.
This shift in the equilibrium position will favour either the forward or reverse reaction depending on the type of constraint imposed on the system.
Hence, If a chemical system is at equilibrium, any change in the system will always result in an increase of the reaction that opposes the change.