In: Chemistry
Consider the following reaction and its equilibrium
constant:
I2(g) + Br2(g) 2 IBr(g) Kc = 1.1 × 102
This reaction mixture contains initially 0.41 M I2 and 0.27 M Br2. Calculate the equilibrium concentration of I2, Br2, and IBr?
Please help with this, Can I find a example similar to this anywhere. I can't figure out some of the parts of this problem.
Consider the following reaction and its equilibrium
constant:
I2(g) + Br2(g) 2 IBr(g) Kc = 1.1 × 102
This reaction mixture contains initially 0.41 M I2 and 0.27 M Br2. Calculate the equilibrium concentration of I2, Br2, and IBr?
Please help with this, Can I find a example similar to this anywhere. I can't figure out some of the parts of this problem.
Ans:
I2(g)+ Br2(g) ↔ 2IBr (g) Kc = 1.1 × 102 =110
Kc = [products]/[reactants] =
([IBr]2)/(([I2])*([Br2]))
ICE table :
Species...Initial...Change...Equilib.....
I2...........0.41M...
-x... 0.41-x....
Br2.........0.27M...
-x... 0.27-x....
IBr......
0..... +2x...
2x ...
Now just plug in the numbers and calculate Kc:
Kc = [products]/[reactants] =
([IBr]2)/(([I2])*([Br2]2))
Kc = ((2x)2)/(( 0.41-x)*( 0.27-x))
110 = ((2x)2)/(( 0.41-x)*( 0.27-x))
110 (0.1107-0.41x-0.27x+x2) = 4x2
110 (0.1107-0.68x+x2) = 4x2
12.177-74.8x+110x2 = 4x2
106x2-74.8x+12.177 = 0
If we solve this quadratic equation we will get x=0.254 or x=0.45
x=0.45 is not possible because initial concentration of I2 is 0.41 M and Br2 is 0.27 M
Equilibrium concentration of I2 = 0.41-x = 0.41-0.254 = 0.156 M
Equilibrium concentration of Br2= 0.27-0.254 = 0.016 M
Equilibrium concentration of IBr = 2*0.254 = 0.508M