Question

At 25 degree celsius, the equilibrium constant Kc for the reaction
2A(g) yields B(g) + C(g)
is 0.035. A mixture of 8.00 moles of B and 12.00 moles of C in a 20.0 L container is allowed to come to equilibrium. What is the equilibrium concentration of A?

A. < 0.100
B. 13.56
C. 0.678
D. 0.339
E. 6.78

Answer 1

write the expression, plug in your values, and solve.

Answer 2

I did but the answer I got wasn't what is given

Answer 3

i forgot to mention that you need an ice table

Answer 4

This is what I have for my ICE table.

2A(g) yields B(g) + C(g)
Initial 0 0.400 0.600
Change -2x +x +x
Equili -2x 0.400+x 0.600+x

Kc = (B)(C)/(A)^2
0.035 = 0.400(0.600)/x^2
0.035(x^2) = 0.240
x^2 = 6.857
x = 2.618587

Answer 5

you need to reverse the signs, you're losing B and C and gaining A

2A(g) yields B(g) + C(g)
Initial 0 0.400 0.600
Change +2x -x -x
Equili +2x 0.400-x 0.600-x

Answer 6

Oh. I see my mistake

Answer 7

0.035(2x) = 0.400(0.600)
0.070x = 0.240
x = 3.42857

Is the answer I got but its still not the answer. Awwwwww!

Answer 8

I think I figure it out. Just plug in the answer back into the Equilibrium part of the ICE table.
So 2(3.43) = 6.84

Answer 9

it should be: \(0.035=\dfrac{[0.400-x][0.600-x]}{[2x]^2} \)

Answer 10

{x=0.3385975230485919, x=0.8241931746258267}

2(0.82)=1.64
2(0.33)=0.66