Chemistry Equilibrium DUHS 2022
PMDC Verified Question 59 of 102
In exothermic reaction, by decreasing the temperature, equilibrium constant:
A
Remains the same
B
Reaction moves backward
C
Decreases
D
Increases
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: Increases
Concept:

For exothermic reactions, heat is considered a product. Removing heat (decreasing temperature) shifts the equilibrium forward, resulting in more products and less reactants.

Formula:

$$ K_c = \frac{[\text{Products}]}{[\text{Reactants}]} $$

Solution:

  • When temperature is decreased, Le Chatelier's Principle dictates a shift to the right to generate more heat.


  • This forward shift drastically increases the concentration of Products in the numerator.


  • Simultaneously, Reactants in the denominator are consumed and decrease.


  • A larger numerator divided by a smaller denominator mathematically results in a larger overall ratio.


  • Therefore, the equilibrium constant \( K_c \) inherently increases.


Why other options are incorrect:

Constants only remain the same if temperature is unchanged. Decreasing would happen in an endothermic reaction.

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