Home › AP Chemistry › Chemistry › Fundamental Equilibrium Concepts › The reaction quotient is useful during a reactio…
The reaction quotient is useful during a reaction because its value:
AStays fixed from the start
BEquals K at every moment
CCannot be calculated at all
DVaries as the reaction proceeds
Answer & Solution
Correct answer: D. Varies as the reaction proceeds
1. The equilibrium constant is a single fixed number at a given temperature.
2. The quotient uses the same expression but with whatever concentrations are present right now.
3. The numerical value of the quotient varies as a reaction proceeds towards equilibrium.
4. Therefore it can serve as a useful indicator of the reaction's status.
5. Comparing it with K tells you which direction the system will move next.
_Source: OpenStax Chemistry 2e (CC BY 4.0), Ch 13 'Fundamental Equilibrium Concepts', sections 13.1-13.4_
Related questions
Many real systems involve coupled equilibria, meaning two reactions that share:Adding 0.10 mol of nitrogen dioxide to a 1.0 litre flask at 25 degrees Celsius left equiliReactions differ from many physical processes in that they may proceed:A reaction quotient equation using absolute concentrations rather than relative values is:Changing the volume of a gas-phase equilibrium changes the concentrations of:Multiplying every stoichiometric coefficient in an equation by a factor changes K:Removing hydrogen iodide from its equilibrium mixture leaves the concentrations of all thrAdding hydrogen or iodine to a hydrogen iodide equilibrium increases the rate of: