Using this data,
2 NO(g) + Cl2(g) == 2 NOCl(g) Kc = 3.20 X 10-3
NO2(g) == NO(g) + ½ O2(g) Kc = 3.93
calculate a value for Kc for the reaction,
NOCl (g) + ½ O2 (g) == NO2 (g) + ½ Cl2 (g)
A. 20.2
B. 2.06 X 10-4
C. 4.49
D. 4.84 X 10-3
E. 0.223
eliminated down to b or d
but going with b unless wrong
I disagree with b AND d.
Use equation 1, take 1/2 of it, and reverse it. K1 for that will be 1/sqrt Kc.
Multiply k1 by equation 2 reversed so k2 = 1/Kc
Then k1*k2 = ?
Check my manipulations to be sure you get the equation in the problem.
when you reverse it do you get a negative?
no negatives
To calculate the value of Kc for the reaction:
1. Start by writing the balanced equation for the reaction:
NOCl (g) + ½ O2 (g) ↔ NO2 (g) + ½ Cl2 (g)
2. Use the given equilibrium constants (Kc values) for the individual reactions to determine the overall Kc for the desired reaction.
The first equation given is:
2 NO(g) + Cl2(g) ↔ 2 NOCl(g) Kc = 3.20 X 10^(-3)
The second equation is:
NO2(g) ↔ NO(g) + ½ O2(g) Kc = 3.93
3. Combine the given equations to get the desired equation:
Multiply the first equation by 2 to balance the number of NO molecules:
4 NO(g) + 2 Cl2(g) ↔ 4 NOCl(g)
Multiply the second equation by 2 to make the NO2 term match:
2 NO2(g) ↔ 2 NO(g) + O2(g)
4. Combine the resulting equations:
4 NO(g) + 2 Cl2(g) ↔ 4 NOCl(g) + O2(g)
Since the overall reaction involves the same number of moles on both sides, we can write the expression for Kc as:
Kc = [NOCl]^4 * [O2] / [NO]^4 * [Cl2]^2
5. Now substitute the given equilibrium constants (Kc values) into the expression:
Kc = (3.20 X 10^(-3))^4 * (3.93) / (3.93)^4 * (3.20 X 10^(-3))^2
Simplify the expression:
Kc = (3.20 X 10^(-3))^2 / (3.93)^3
6. Calculate the result:
Kc ≈ 2.06 X 10^(-4)
Based on the calculations, the value of Kc for the reaction is approximately 2.06 X 10^(-4). So, the correct answer is B.