What condition favours the formation of the product for the endothermic reaction, \(N_2O_{4(g)} \rightarrow 2NO_{2(g)}\)?...
What condition favours the formation of the product for the endothermic reaction, \(N_2O_{4(g)} \rightarrow 2NO_{2(g)}\)?
- A) A decrease in pressure
- B) A decrease in volume
- C) An increase in pressure
- D) A constant volume
Correct Answer: A) A decrease in pressure
Explanation
The given reaction is an endothermic reaction, which means it absorbs heat from its surroundings. The reaction is represented as:
\(N_2O_{4(g)} \rightarrow 2NO_{2(g)}\)
To understand the conditions that favor the formation of the product, we need to consider Le Chatelier's principle. Le Chatelier's principle states that if a system at equilibrium is subjected to a change in conditions, the system will adjust itself to counteract the change and restore a new equilibrium.
For endothermic reactions, an increase in temperature favors the forward reaction, while a decrease in temperature favors the reverse reaction. In this case, we are not given any information about the temperature, but we can analyze the effect of pressure and volume on the reaction.
When analyzing the effect of pressure, we can see that there is one mole of reactant and two moles of product. According to Le Chatelier's principle, if we decrease the pressure, the reaction will shift towards the side with more moles of gas to compensate for the change. In this case, that is the side of the products (2 moles of NO?). So, a decrease in pressure will favor the formation of the product.
Option A, a decrease in pressure, is the correct answer. Other options like a decrease in volume (Option B) and an increase in pressure (Option C) would actually favor the reverse reaction, as they would force the system to shift towards the side with fewer moles of gas (the reactant side). Option D, a constant volume, would not have any significant effect on the reaction.