## Chemistry: Principles and Practice (3rd Edition)

CS$_2$ + 3O$_2$ ➔ 2SO$_2$ + CO$_2$
Let us write out the unbalanced equation first. Carbon sulfide is a molecular compound, so the numbers of each atom in the compound are already given. We have carbon and sulfur bound in a 1:2 ratio. Oxygen usually exists as a diatomic molecule. Sulfur dioxide is also a molecular compound, so the numbers of each atom are already given. We have sulfur and oxygen in a 1:2 ratio. Carbon dioxide is also a molecular compound, so we can see that we have one carbon atom for every two oxygen atoms. Here is the unbalanced chemical equation for this reaction: CS$_2$ + O$_2$ ➔ SO$_2$ + CO$_2$ Now we need to balance this equation. We look first at the carbon atoms. We have 1 on the left and 1 on the right. We are balanced in terms of carbon atoms. We now look at the sulfur atoms. We have 2 on the left and 1 on the right. We need to add a 2 in front of SO$_2$ to balance the sulfur atoms. CS$_2$ + O$_2$ ➔ 2SO$_2$ + CO$_2$ Let's check the oxygen atoms now. We have 2 on the left and 6 on the right. Let's add a 3 in front of O$_2$ to balance the oxygen atoms. CS$_2$ + 3O$_2$ ➔ 2SO$_2$ + CO$_2$ Now let's check the numbers of atoms in the reactants and the products. Reactants/Products: carbon: 1/1 sulfur: 2/2 oxygen: 6/6