To find the molar ratios of substances in a chemical equation, you can follow these simple steps:

1. Write the Balanced Equation: First, make sure your chemical equation is balanced. This means the number of atoms for each element should be the same on both sides of the equation.

   For example, when propane burns, the balanced equation looks like this: $\text{C}_3\text{H}_8 + 5 \text{O}_2 \rightarrow 3 \text{CO}_2 + 4 \text{H}_2\text{O}$

2. Identify Coefficients: The numbers in front of the substances, called coefficients, show the molar ratios. In the example above:

   • Propane has a coefficient of 1
   • Oxygen has a coefficient of 5
   • Carbon dioxide has a coefficient of 3
   • Water has a coefficient of 4

3. Understand Molar Ratios: You can express molar ratios as fractions. For instance:

   • The ratio of propane to oxygen is $1:5$
   • The ratio of propane to carbon dioxide is $1:3$
   • The ratio of carbon dioxide to water is $3:4$

4. Use Ratios for Calculations: These ratios are very helpful when figuring out how much of each substance is needed or produced. For example, if you start with 2 moles of propane, you will need $2 \times 5 = 10$ moles of oxygen.

5. Practice with Different Equations: The best way to get good at this is to practice with a variety of chemical equations. This will help you feel comfortable using molar ratios in your calculations.