Question

Consider the following reaction where Kc = 10.5 at 350 K: 2 CH2Cl2 (g) CH4 (g) + CCl4 (g) A reaction mixture was found to contain 1.15×10-2 moles of CH2Cl2 (g), 5.11×10-2 moles of CH4 (g), and 3.61×10-2 moles of CCl4 (g), in a 1.00 liter container. Indicate True (T) or False (F) for each of the following: ___ 1. In order to reach equilibrium CH2Cl2(g) must be produced . ___ 2. In order to reach equilibrium Kc must increase . ___ 3. In order to reach equilibrium CH4 must be produced . ___ 4. Qc is less than Kc. ___ 5. The reaction is at equilibrium. No further reaction will occur.

Answer 1

The given reaction will proceed towards the right to produce CH4 (g) and CCl4 (g) at the expense of CH2Cl2 (g). The statement that CH2Cl2 (g) must be produced to reach equilibrium is false. The reaction is not at equilibrium, and further reaction will occur.

Step-by-step explanation:

The given reaction is:

2 CH2Cl2 (g) → CH4 (g) + CCl4 (g)

To determine whether certain statements are true or false, we need to consider the given equilibrium constant (Kc) and the concentrations of the reactants and products in the reaction mixture.

1. False. In order to reach equilibrium, CH2Cl2 (g) must be consumed, not produced. This is because the forward reaction converts CH2Cl2 (g) into CH4 (g) + CCl4 (g).
2. False. In order to reach equilibrium, Kc does not need to increase. Kc remains constant and represents the ratio of the concentrations of products to the concentrations of reactants at equilibrium.
3. True. In order to reach equilibrium, CH4 (g) must be produced. This is because the forward reaction converts CH2Cl2 (g) into CH4 (g) + CCl4 (g).
4. False. Qc represents the ratio of the concentrations of products to the concentrations of reactants at any given point in the reaction. If Qc < Kc, it means there are relatively fewer products than what is required at equilibrium. So, Qc is greater than Kc in this case.
5. False. The reaction is not at equilibrium because Qc is greater than Kc. The reaction will proceed towards the right, favoring the formation of CH4 (g) and CCl4 (g) at the expense of CH2Cl2 (g).

Answer 2

The given reaction is:

2CH₂Cl₂ (g) ⇒ CH₄ (g) + CCl₄ (g), the reaction Q is,

Q = [CH₄][CCl₄]/[CH₂Cl₂]²

Based on the given question, the values of Kc is 10.5 at 350 K, and the moles of CH₂Cl₂ is 1.15 × 10⁻² moles, moles of CCl₄ is 3.61 × 10⁻² moles, and the moles of CH₄ is 5.11 × 10⁻² moles. Now putting the values we get,

Q = (5.11 × 10⁻²) (3.61 × 10⁻²) / (1.15 × 10⁻²)²

Q = 13.95

It is evident that the value of Q is more than Kc, thus, the reaction will shift in backward direction as the concentration of products is more than the reactants.

1. The given statement is false, as the concentration of reactant is required to increase, and the concentration of product is required to get consumed to attain equilibrium.

2. The given statement is false, Kc or equilibrium constant is a fixed quantity, while there can be a reduction or enhancement in the Q based upon the condition.

3. In the statement, CH₄ must be consumed not produced, it is not spell correctly. Now the given statement will become true, as to attain equilibrium the reaction is required to shift in backward direction, which is only feasible when there is consumption of the concentration of products.

4. The given statement is false, as based on the calculations, Q > Kc.

5. The statement is false as Q is not equal to Kc, it is greater than Kc.