## 5.55

$\Delta G^{\circ}= \Delta H^{\circ} - T \Delta S^{\circ}$

$\Delta G^{\circ}= -RT\ln K$

$\Delta G^{\circ}= \sum \Delta G_{f}^{\circ}(products) - \sum \Delta G_{f}^{\circ}(reactants)$

dtolentino1E
Posts: 101
Joined: Thu Jul 11, 2019 12:17 am

### 5.55

A reaction used in the production of gaseous fuels from coal, which is mainly carbon, is C(s) + H2O(g) <--> CO(g) + H2(g). (a) Evaluate K At 900 K, given that the standard Gibbs free energies of formation of CO(g) and H2O(g) at 900 K are 2191.28 kJ/mol and 2198.08 kJ/mol, respectively. (b) A sample of graphite of mass 5.20 kg and 125 g of water were placed into a 10.0-L container and heated to 900 K. What are the equilibrium concentrations?

for part b), the solutions manual excludes C(s) in the final equilibrium concentrations. why??

Elena Bell 1C
Posts: 64
Joined: Thu Jul 11, 2019 12:16 am

### Re: 5.55

Since C(s) is in solid form, it is not included in the equation for the equilibrium constant. There is no concentration for C(s) at equilibrium because it does not change much from the initial concentration and is not related to equilibrium.

Sofia Barker 2C
Posts: 101
Joined: Wed Sep 18, 2019 12:21 am

### Re: 5.55

C(s) is irrelevant because it is in solid form. The concentrations of solids do not change throughout a reaction, which is why solids are considered pure substances.

Megan Vu 1J
Posts: 101
Joined: Thu Jul 25, 2019 12:15 am

### Re: 5.55

C is not included because it is a solid. Since it is a solid, it is not able to be included in the chemical equation for ICE because we do not include solids or liquids.

You should only include aqueous solutions or gases, and then, you are able to find the equilibrium concentrations for the question.

AKhanna_3H
Posts: 104
Joined: Wed Sep 18, 2019 12:19 am

### Re: 5.55

Solids and liquids are not included in equilibrium constants. Only gases and aqueous solutions are included.