For the equilibrium system below, which of the following would decrease the concentration of 𝑃𝐶𝑙3(𝑔)?

Question

For the equilibrium system below, which of the following would decrease the concentration of 𝑃𝐶𝑙3(𝑔)?

𝑃𝐶𝑙3(𝑔) + 𝐶𝑙2(𝑔) ↔ 𝑃𝐶𝑙5(𝑔) + 45𝑘𝐽

a. Increased temperature

b. Decreased pressure

c. Increased [𝑃𝐶𝑙5]

d. Increased [𝐶𝑙2]

Answer 1

Adding Cl2 would increase the stress on the reactant side as an excess to the equilibrium. To relieve the stress the reaction would shift to the right decreasing PCl3 which would be reacting with the excess Cl2 until a new equilibrium is established.

Increasing the temperature, decreasing pressure or increasing PCl5 places the stress factors on the product side causing the reaction to shift left to relieve the stress and PCl3 would increase.

'D' choice is the best answer. Hope this helps.

Answer 2

You may also wish to see my post on the question from 'Urgent' at 7:02. Just before your post. Same kind of question. Ya'll must be in the same class.

Answer 3

To determine which option would decrease the concentration of 𝑃𝐶𝑙3(𝑔), we need to consider Le Chatelier's principle. According to this principle, if a change is applied to a system at equilibrium, the system will shift in such a way as to counteract the change.

Let's analyze each option one by one:

a. Increased temperature: According to Le Chatelier's principle, increasing the temperature will cause the equilibrium to shift in the direction that consumes heat. Since the reaction is endothermic (heat is on the product side), increasing the temperature will favor the forward reaction. As a result, the concentration of 𝑃𝐶𝑙3(𝑔) will decrease.

b. Decreased pressure: According to Le Chatelier's principle, decreasing the pressure will cause the equilibrium to shift in the direction that reduces the number of gas molecules. In this case, there are the same number of gas molecules on both sides of the equation, so changing the pressure will not affect the equilibrium position. Therefore, the concentration of 𝑃𝐶𝑙3(𝑔) will not change.

c. Increased [𝑃𝐶𝑙5]: According to Le Chatelier's principle, increasing the concentration of 𝑃𝐶𝑙5 will cause the equilibrium to shift in the direction that consumes 𝑃𝐶𝑙5. Since 𝑃𝐶𝑙5 is on the product side, the reaction will shift to the left, resulting in the decrease in the concentration of 𝑃𝐶𝑙3(𝑔).

d. Increased [𝐶𝑙2]: According to Le Chatelier's principle, increasing the concentration of 𝐶𝑙2 will cause the equilibrium to shift in the direction that consumes 𝐶𝑙2. Since 𝐶𝑙2 is on the reactant side, the reaction will shift to the right, resulting in the increase in the concentration of 𝑃𝐶𝑙3(𝑔), not the decrease.

Therefore, the correct option that would decrease the concentration of 𝑃𝐶𝑙3(𝑔) is a. Increased temperature.

Answer 4

To determine which factor would decrease the concentration of PCl3(g) in the given equilibrium system, let's analyze the Le Chatelier's principle.

Le Chatelier's principle states that a system at equilibrium will shift to counteract any changes applied to it in order to maintain equilibrium.

a. Increased temperature:
According to Le Chatelier's principle, an increase in temperature will shift the equilibrium in the direction that absorbs heat. In this case, the forward reaction (the one that consumes heat) is the conversion of PCl3(g) and Cl2(g) to PCl5(g) and is represented by the equation:
PCl3(g) + Cl2(g) ↔ PCl5(g) + 45kJ

Since the forward reaction is endothermic (heat-absorbing), an increase in temperature will favor the endothermic direction to absorb the excess heat. Therefore, the concentration of PCl3(g) would decrease.

b. Decreased pressure:
The given equation does not contain any gaseous reactants except for PCl3(g) and Cl2(g). According to Le Chatelier's principle, a decrease in pressure will shift the equilibrium in the direction that reduces the number of gas molecules. Since both forward and backward reactions have the same number of gas molecules, changing the pressure will not affect the concentration of PCl3(g).

c. Increased [PCl5]:
An increase in the concentration of PCl5(g) would shift the equilibrium towards the reactants (reverse reaction) to counteract the change and reduce the excess of PCl5(g). Therefore, the concentration of PCl3(g) would decrease.

d. Increased [Cl2]:
An increase in the concentration of Cl2(g) would shift the equilibrium towards the products (forward reaction) to counteract the change and consume the excess Cl2(g). Therefore, the concentration of PCl3(g) would decrease.

Based on the analysis, options a, c, and d would decrease the concentration of PCl3(g). Therefore, the correct answer is: a. Increased temperature, c. Increased [PCl5], and d. Increased [Cl2].