Let's analyze the given chemical reaction and determine the direction in which the reaction shifts when [tex]\( O_2 \)[/tex] is added to the solution:
[tex]\[ 2 SO_2(g) + O_2(g) \rightleftharpoons 2 SO_3(g) + 198 \text{ kJ} \][/tex]
When considering how a reaction responds to a change in conditions, we use Le Chatelier's principle. This principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium moves to counteract the change.
In this case, the disturbance is the addition of [tex]\( O_2 \)[/tex]. Here's the step-by-step process:
1. Identify the Disturbance:
- [tex]\( O_2 \)[/tex] is added to the system, which increases its concentration.
2. Determine the Response According to Le Chatelier's Principle:
- The system will attempt to reduce the increased concentration of [tex]\( O_2 \)[/tex].
3. Shift in Equilibrium:
- Because [tex]\( O_2 \)[/tex] is a reactant in the forward reaction, the system can counteract the increase by using up the added [tex]\( O_2 \)[/tex] to form more [tex]\( SO_3 \)[/tex].
- Therefore, the equilibrium will shift to the right —toward the products— to produce more [tex]\( SO_3 \)[/tex].
Conclusion:
The reaction shifts to the right or to products when [tex]\( O_2 \)[/tex] is added to the solution.
Thus, the correct answer is:
C. The reaction shifts right or to products.