Chemistry Equilibrium ETEA 2024
PMDC Verified Question 16 of 102
In the production of \( \text{SO}_3 \), from \( \text{SO}_2 \) and Oxygen, the yield of \( \text{SO}_3 \), is increased by
A
Adding a catalyst
B
Adding more \( \text{SO}_2 \)
C
Increasing temperature
D
Removing oxygen
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Adding more \( \text{SO}_2 \)
Concept:

This is an application of Le Chatelier's Principle regarding concentration changes in the Contact Process.

Formula:

$$ 2\text{SO}_{2(g)} + \text{O}_{2(g)} \rightleftharpoons 2\text{SO}_{3(g)} \quad \Delta H = \text{-ive} $$

Solution:

  • According to Le Chatelier, adding more of a reactant creates an imbalance, forcing the system to consume the excess.


  • By continuously adding more \( \text{SO}_2 \) (a reactant), the equilibrium is constantly shifted forward (to the right).


  • This forward shift directly increases the production and yield of the \( \text{SO}_3 \) product.


Why other options are incorrect:

Catalysts do not increase yield, only rate. Increasing temperature decreases yield (it's exothermic). Removing oxygen would shift the reaction backward, ruining yield.

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