[Nathaniel]

4. For the following equilibrium expression and its value, write a balanced equation for the reverse reaction and calculate the value of the equilibrium constant for the reverse reaction, K’:

[C2H6(s)][H2(s)] / [CH4(s)] = 9.5 x 10^-13

I got this answer for the balanced equation: 6C2H6(s) + H2(s) ----> 4CH(s)

How is the balanced equation for the reverse reaction written?

   

[flightman233]

I think you need to check a few things before we continue with this problem.

First being the states that these reactants and products are in, H2(s) is highly unlikely and I think you meant to type H₂(g).

Also if the equilibrium expression you typed is correct the balanced equation must follow suit, example if there are 2A + 3C --> A₂C₃.  Then the resulting expression should be K = [A₂C₃] / [A]² [C]³

Check on these things then let us continue.

[Nathaniel]

Alright, so my balanced equation should be:

2CH4 --> C2H6 + H2

What is the balacned equation for the reverse direction?

[enahs]

What is the balacned equation for the reverse direction?

Point the arrow in the other direction.

Or switch reacts to products and products to reactants.

[Nathaniel]

Pointing the arrow in the other direction I get

2CH4 <---- C2H6 + H2

How do I calculate the value of the equilibrium constant for the reverse reaction, K'?

[Astrokel]

Pointing the arrow in the other direction I get

2CH4 <---- C2H6 + H2

whats this reaction? o.0

How do I calculate the value of the equilibrium constant for the reverse reaction, K'?

K = [C2H6] [H2] / [CH4]^2 = 9.5 X 10^-13
K' = [CH4]^2 / [C2H6][H2] = ?

sorta like
K = A/B
K'= B/A

See the relationship?

[Nathaniel]

Where does the 9.5 X 10^-13 value fit in?

[flightman233]

Basically what he is telling you is that you have your value for K which points in one direction, so in order to find out the reverse reaction you have to just take the inverse of K. 

K^-1 = 1/K   

[weiguxp]

reverse would still be products/reactants hence it will become: [CH4(s)] / [C2H6(s)][H2(s)]

so yeah, K^-1 as previously stated