How do you construct a chemical equation from a word equation?

To construct a chemical equation from a word equation, you need to identify the reactants, products, and ensure the equation is balanced.

Firstly, you need to identify the reactants and products in the word equation. The reactants are the substances that are reacting, and they are usually mentioned at the beginning of the sentence. The products are the substances that are formed as a result of the reaction, and they are usually mentioned at the end of the sentence. For example, in the word equation "Iron reacts with oxygen to form iron(III) oxide", iron and oxygen are the reactants, and iron(III) oxide is the product.

Next, you need to write the chemical symbols for each of the reactants and products. The chemical symbol for iron is Fe, for oxygen is O, and for iron(III) oxide is Fe2O3. So, the chemical equation becomes "Fe + O → Fe2O3".

However, this equation is not balanced. A balanced chemical equation has the same number of each type of atom on both sides of the equation. In this case, there are two oxygen atoms on the right side of the equation, but only one on the left. To balance the equation, you can add a coefficient in front of the oxygen on the left side, so the equation becomes "Fe + 1.5O2 → Fe2O3". But, since we can't have half molecules in a reaction, we multiply the entire equation by 2 to get "2Fe + 3O2 → 2Fe2O3".

Remember, it's important to always check that your final equation is balanced. This means that there should be the same number of each type of atom on both sides of the equation. If it's not balanced, you'll need to adjust the coefficients until it is.