Predict the shift of equilibrium for each of the following conditions in the following reaction involving gaseous reactants and products:
N2 + 3H2 = 2NH3 + heat
A. the pressure is increased.
b. the temperature is decreased.
A. When the pressure is increased, the equilibrium will shift towards the side with fewer moles of gas. In this reaction, there are 4 moles of gas on the left side (N2 + 3H2), and 2 moles of gas on the right side (2NH3). Therefore, the equilibrium will shift to the right, favoring the formation of more NH3.
B. When the temperature is decreased, the equilibrium will shift in the direction of the reaction that generates heat. In this case, the forward reaction (N2 + 3H2 -> 2NH3 + heat) is exothermic, meaning it releases heat. So, by decreasing the temperature, the equilibrium will shift towards the exothermic reaction to generate more heat, which is the forward reaction from left to right.
To predict the shift of equilibrium, we need to consider how the changes in pressure and temperature affect the reaction involving gaseous reactants and products.
A. When the pressure is increased:
According to Le Chatelier's principle, an increase in pressure will cause the equilibrium to shift in the direction that produces fewer moles of gas. In this reaction, the left side (N2 + 3H2) has a total of 4 moles of gas, while the right side (2NH3) has 2 moles of gas. Therefore, an increase in pressure will shift the equilibrium to the right. It will favor the forward reaction (formation of NH3) to reduce the total number of gas molecules.
B. When the temperature is decreased:
For an exothermic reaction like this one ('+ heat' indicates that heat is a product), decreasing the temperature will shift the equilibrium to the right, favoring the forward reaction that generates heat. According to Le Chatelier's principle, a decrease in temperature causes the system to try to compensate by producing more heat. Therefore, the reaction will favor the forward reaction (formation of NH3) to generate more heat.
In summary:
A. Increasing the pressure will shift the equilibrium to the right.
B. Decreasing the temperature will shift the equilibrium to the right.