The reactions shown here can be combined to make the overall reaction C(s) + H2O(g) ⇌ CO(g) + H2(g) by reversing some and/or dividing all the coefficients by a number. a. C(s) + O2(g) → CO2(g) K=1.363×10^69 b. 2 H2(g) + O2(g) → 2 H2O(g) K=1.389×10^80 c. 2CO(g) + O2 (g) → 2 CO2(g) K=1.477×10^90

Explanation:

Overall reaction :

C(s) + H2O(g) ⇌ CO(g) + H2(g)

First Reaction :

C(s) + O2(g) → CO2(g)

Second Reaction :

2 H2(g) + O2(g) → 2 H2O(g)

Third Reaction :

2CO(g) + O2 (g) → 2 CO2(g)

To obtain the overall reaction

- Multiply the first reaction by 2. The equation we have is;

2C(s) + 2O2(g) → 2CO2(g)

- Add the reaction with the reversed second reaction. The equation we have is given as;

2C(s) + 2O2(g) + 2 H2O(g)   → 2 H2(g) + O2(g) +  2CO2(g)

Simplifying we have;

2C(s)  + 2 H2O(g)  + O2(g) → 2 H2(g) +  2CO2(g)

- Add the new equation with the reversed third equation. We have;

2C(s)  + 2H2O(g) + 2CO2(g) + O2(g)  → 2 H2(g) +  2CO2(g)  + 2CO(g) + O2 (g)

Simplifying we have;

2C(s)  + 2 H2O(g)  → 2 H2(g)  + 2CO(g)

Divide the reaction by 2. We have;

C(s) + H2O(g) ⇌ CO(g) + H2(g)

im not exactly sure but i think its b!