Chemistry 102: Equilibrium: Write the balanced equation based off a photo

Question

Chemistry 102: Equilibrium: balance equation from photo

This image shows a mixture of steam and carbon monoxide reacting to reversibly produce carbon dioxide and hydrogen gas. Write the balanced chemical equation which is taking place in the mixture. 

Be sure to include the physical states of each species.

Answer 1

To solve an answer like this where you have the exact amount of molecules, you don't need to do much balancing. Remember that oxygen is typically shown as red, hydrogen in white, and carbon in black. Just follow three steps:

1) Write the equation with every molecule shown in it, as such:

4H2O + 4CO -> 2H2O + 2CO + 2CO2 + 2H2

2) Subtract molecules that are on both sides of the equation. In this case, subtract 2H20 and 2CO from both sides so that you have:

2H2O + 2CO -> 2CO2 + 2H2

3) Now balance the equation. It's unnecessary to state you have two of each molecule, so divide by 2:

H2O + CO -> CO2 + H2

This is correct, but it's always important to double check. Make sure you have the same number of Hydrogens, Carbons, and Oxygens on both sides. In this case you have 2 Hydrogens, 2 Oxygens, and 1 Carbon on both sides.