Consider the reaction:
2N2O (g) 2N2 (g) + O2 (g)
The values of Kc at different temperatures are:
Which statement is correct at a higher temperature?
A. The forward reaction is favoured.
B. The reverse reaction is favoured.
C. The rate of the reverse reaction is greater than the rate of the forward reaction.
D. The concentration of both reactants and products increase.
To determine which statement is correct at a higher temperature, we need to analyze the effect of temperature on the equilibrium position of the reaction.
The reaction given is a decomposition reaction where N2O (nitrous oxide) decomposes into N2 (nitrogen gas) and O2 (oxygen gas).
When the reaction is at equilibrium, the ratio of the concentrations of the products (N2 and O2) to the concentration of the reactant (N2O) is described by the equilibrium constant Kc.
Let's consider the effect of temperature on this reaction:
1. If the temperature is increased:
- According to Le Chatelier's principle, when the temperature of an equilibrium system is increased, the equilibrium will shift in the direction that consumes heat (endothermic direction).
- In this reaction, the forward reaction is endothermic because it absorbs heat to break the N2O molecule into N2 and O2.
- Therefore, increasing the temperature will favor the forward reaction (to the right), leading to an increase in the concentration of N2 and O2.
2. If the forward reaction is favored:
- The forward reaction will produce more products (N2 and O2), resulting in an increase in the concentration of products compared to the reactant.
- This means that at a higher temperature, the concentration of the reactant (N2O) will decrease, while the concentration of the products (N2 and O2) will increase.
Based on the above analysis, we can conclude that statement D is correct: at a higher temperature, the concentration of both reactants and products increase.
To determine which statement is correct at a higher temperature, let's take a look at the reaction and the effect of temperature on the equilibrium position.
The reaction is: 2N2O (g) ⇌ 2N2 (g) + O2 (g)
At a higher temperature:
- According to Le Chatelier's principle, an increase in temperature favors the endothermic direction of the reaction. In this case, the forward reaction is endothermic (since it absorbs heat).
- As a result, the equilibrium will shift in the endothermic direction (to the right).
- This means that the forward reaction is favored at higher temperatures (statement A is correct).
- By favoring the forward reaction, the concentration of the reactants (2N2O) will decrease while the concentration of the products (2N2 and O2) will increase.
Hence, the correct statement at a higher temperature is:
A. The forward reaction is favored.