Answer: Concentrations remain constant.
- A Concentrations of reactants equal products
- B All reactions stop
- C Concentrations remain constant
- D Temperature changes
Correct answer: C. Concentrations remain constant
Explanation: At equilibrium, concentrations of all species remain constant (not necessarily equal).
As the reaction proceeds, reactant concentration falls and product concentration rises until both level off at equilibrium.
Concept context
When forward and reverse reaction rates are equal, equilibrium is reached. Learn about Kc, Kp, Le Chatelier's principle, and acid-base equilibria, including pH, buffer solutions, and solubility product.