5G.21

[Aman Sankineni 2L]

5G.21 Calculate the equilibrium constant at 25 8C for each of the
following reactions, by using data in Appendix 2A:
(a) the combustion of hydrogen: 2 H2(g) 1 O2(g) Δ 2 H2O(g)
(b) the oxidation of carbon monoxide: 2 CO(g) 1O2(g) Δ
2 CO2(g)
(c) the decomposition of limestone: CaCO3(s) Δ CaO(s) 1
CO2(g)

How would you go about solving this problem?

[Nick Fiorentino 1E]

You’d use the equation G=-RTlnK. You want to solve for K so you’d rearrange the equation to be -G/RT=lnK. You have all the values needed besides G which you can get from appendix 2A, and then you solve for K!

[Fatemah Yacoub 1F]

Everything given to you in the problem is either a constant or experimentally determined, so when you rearrange the equation to solve for K, you exponentiate the G/-RT, to give you the answer.

[Matthew ILG 1L]

I have tried part A several times but I keep coming up with K=1.096. How does the book manage to get 1.0 x 10^80. Does it have something to do with the 2 in front of H20 in the balanced equation?
The only Standard Gibbs free energy of formation given by the appendix is -228.57 for H2O I believe.

[Kavya Immadisetty 2B]

I have tried part A several times but I keep coming up with K=1.096. How does the book manage to get 1.0 x 10^80. Does it have something to do with the 2 in front of H20 in the balanced equation?
The only Standard Gibbs free energy of formation given by the appendix is -228.57 for H2O I believe.

Make sure that you multiply the gibbs free energy of the equatoin by 10^3 to convert from kJ to J