Question

Use the reactions below to predict the equilibrium constant for the reaction 2A(g)<->3D(g)

A(s)<->1/2B(g)+C(g) k1=0.0334

3D(g)<->B(g)+2C(g) k2=2.35

I know that you have to make modifications according to the stoichiometric coeffecients. So do I divide k1 by 2 and the multiply that by the inverse of 2.35 (which = 1/2.35 because the equation is reversed)?

I got this answer, is this correct?
0.0034/2=0.0167*(1/2.35)
=0.0071

is this correct?

Answer 1

If I understand what you did, I disagree with the answer. Dividing k1 by 2 means you have the reacton 1/2 A --> 1/4 B and that won't add up to anything.
I think what you want to do is to multiply equation 1 by 2 to give you
2A ==>B + 2C
Then reverse equation 2 to give
2C + B ==> 3D
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Then add those two equations to obtain
2A ==> 3D which is what the problem asked for.
So you want to square k1 and reverse k2, then multiply those.
Check me out on that.