If Q is less than K, what happens to the system?

If Q is less than K, what happens to the system?

• A. The system shifts to the left toward reactants
• B. The reaction has no net change
• C. The system shifts to the right toward products
• D. The temperature must increase

Answer: (C)

Understanding how a system at equilibrium responds when the reaction quotient Q compares to the equilibrium constant K is key. If Q is less than K, there aren’t enough products relative to what the equilibrium ratio dictates. The system responds by proceeding in the forward direction, toward more products and fewer reactants, until Q rises to match K. Temperature isn’t specified here, and K would only change if temperature changed. So the correct behavior is a shift to the right toward products.

Understanding how a system at equilibrium responds when the reaction quotient Q compares to the equilibrium constant K is key. If Q is less than K, there aren’t enough products relative to what the equilibrium ratio dictates. The system responds by proceeding in the forward direction, toward more products and fewer reactants, until Q rises to match K. Temperature isn’t specified here, and K would only change if temperature changed. So the correct behavior is a shift to the right toward products.