When the concentration of I2 is increased to 1.5 M, the ratio of products to reactants is 28. The equilibrium constant for the reaction is 83. In which direction will the reaction shift to regain equilibrium?
reactants ==> products
K = 83 = (products)/(reactants)
Q = 28 which means products are too small and reactants too large. That's the only way you can get a smaller number than Kc. Reaction must shift to the right.
Actually, you don't need to know Q = 28 to predict the same thing.
reactants = products.
You ADD to make reactants 1.5 M (and nothing else). Therefore, you know that adding reactants will force the equilibrium to the right.
To determine the direction in which the reaction will shift, you need to compare the current ratio of products to reactants (Q) with the equilibrium constant (K).
Given that the equilibrium constant for the reaction is 83, and the ratio of products to reactants is 28 when the concentration of I2 is increased to 1.5 M, we can calculate the current value of Q.
Q = [Products] / [Reactants]
If the current Q value is less than the equilibrium constant (Q < K), the reaction will shift towards the products to reach equilibrium. If the current Q value is greater than the equilibrium constant (Q > K), the reaction will shift towards the reactants to reach equilibrium.
Let's calculate the Q value:
Q = [Products] / [Reactants]
Q = 28 / 1
Since Q is 28 and K is 83, we have Q < K. Therefore, the reaction will shift towards the products to regain equilibrium.
To determine the direction in which the reaction will shift to regain equilibrium, we need to compare the current ratio of products to reactants with the equilibrium constant (K) for the reaction.
For the reaction:
I2 ⇌ (products)
Given:
- Concentration of I2 = 1.5 M
- Ratio of products to reactants = 28
- Equilibrium constant (K) = 83
The equilibrium constant (K) is given by the expression:
K = [products] / [reactants]
To find out the concentrations of the products and reactants, we'll assign variables to them. Let's assume that [products] = p and [reactants] = r.
Based on the given ratio, we have:
28 = p / r
Now, let's consider the concentration of I2. At the current concentration of 1.5 M, we know that the concentration of reactants (I2) is higher than the concentration of products. Therefore, we can represent the concentration of reactants as I2 = r' and the concentration of products as (I2)n = p'.
Now, let's rewrite the expression for the equilibrium constant (K):
K = [(I2)n] / I2
Substituting the known values:
83 = p' / (1.5)
Simplifying:
83 * 1.5 = p'
p' = 124.5
Now, let's compare the current ratio of products to reactants (28) with the calculated value (p' / r'):
28 = 124.5 / r'
Cross-multiplying:
28 * r' = 124.5
r' = 124.5 / 28
r' ≈ 4.45
This means that the concentration of reactants (I2) at equilibrium should be around 4.45 M to achieve a product-to-reactant ratio of 28.
Since the current concentration of I2 is 1.5 M (less than the equilibrium concentration of 4.45 M), the reaction will shift to the right (forward) to reach the new equilibrium. This indicates that more products will be formed as the reaction progresses to regain equilibrium.