A 20.0 L reaction vessel contains 0.016 moles CO2, 1.05 moles of CO, and 2.00 moles of C. The mixture is approaching the following equilibrium:
CO2(g) + C(s) <--> 2CO(g)
a) Calculate the reaction quotient Q.
b) If value of K is 1.17, predict which direction the reaction will go in order to reach equilibrium (to the right, to the left, or no change). Explain your answer.
For a), I get 3.45 for Q. For b), I said that the reaction will shift left to reach equilibrium because Q > K.
I agree with both.
Great, thanks!
For part (a), to calculate the reaction quotient (Q), we need to express the concentrations of the reactants and products. The reaction quotient is calculated by dividing the product of the concentrations of the products raised to their stoichiometric coefficients by the product of the concentrations of the reactants raised to their stoichiometric coefficients.
Given the following balanced equation:
CO2(g) + C(s) ⇌ 2CO(g)
The stoichiometric coefficients are:
CO2: 1
C: 1
CO: 2
The initial concentrations of CO2, CO, and C are:
[CO2] = 0.016 moles / 20.0 L = 0.0008 M
[CO] = 1.05 moles / 20.0 L = 0.0525 M
[C] = 2.00 moles / 20.0 L = 0.1 M
Using these concentrations, we can calculate the reaction quotient:
Q = ([CO] ^ 2) / ([CO2] * [C])
= (0.0525 M ^ 2) / (0.0008 M * 0.1 M)
= 3.45
So, your answer for part (a) is correct.
For part (b), to determine the direction the reaction will go in order to reach equilibrium, we compare the reaction quotient (Q) with the equilibrium constant (K).
If Q > K, the reaction will shift in the reverse (left) direction to reach equilibrium.
If Q < K, the reaction will shift in the forward (right) direction to reach equilibrium.
If Q = K, the reaction is already at equilibrium, and there will be no change.
In this case, Q = 3.45 and K = 1.17.
Since Q > K, the reaction will shift in the reverse (left) direction to reach equilibrium.
So, your answer for part (b) is also correct. The reaction will shift to the left to reach equilibrium because Q > K.
To calculate the reaction quotient Q, you need to determine the concentrations of the reactants and products using the given information. The reaction quotient is calculated in the same way as the equilibrium constant (K), but it is evaluated at any point in the reaction, not just at equilibrium.
a) To calculate Q, you need to express the concentration of each species involved in the reaction. In this case, the concentrations will be expressed in terms of moles per liter (Molarity).
Given:
Volume of reaction vessel (V) = 20.0 L
Moles of CO2 = 0.016 mol
Moles of CO = 1.05 mol
Moles of C = 2.00 mol
The reaction is: CO2(g) + C(s) <--> 2CO(g)
The concentration of CO2, [CO2], can be calculated as:
[CO2] = moles of CO2 / volume of reaction vessel
= 0.016 mol / 20.0 L
= 0.0008 M
The concentration of CO, [CO], can be calculated as:
[CO] = moles of CO / volume of reaction vessel
= 1.05 mol / 20.0 L
= 0.0525 M
The reaction has no solid C(s), so the concentration of C is not included in the calculation.
Now you can calculate the reaction quotient Q using these concentrations:
Q = (concentration of CO)^2 / (concentration of CO2)
= (0.0525 M)^2 / (0.0008 M)
= 3.445 M
Therefore, the value of Q is 3.445 (rounded to the nearest thousandth).
b) To determine the direction in which the reaction will proceed to reach equilibrium, you compare the reaction quotient (Q) to the equilibrium constant (K).
If Q > K, it means the reaction has a higher concentration of products compared to the equilibrium state. Therefore, the reaction will shift in the reverse direction, or to the left, to decrease the product concentration and reach equilibrium.
Since Q (3.445) is greater than K (1.17) for this reaction, the prediction is correct that the reaction will shift to the left in order to reach equilibrium.