Combustion analysis is a technique used to determine the elemental composition of a compound containing carbon, hydrogen, and sometimes nitrogen. Here are some key concepts to understand when studying combustion analysis:

1. Combustion analysis involves burning a sample of the compound in excess oxygen to convert all of the carbon to carbon dioxide and all of the hydrogen to water.

2. The amount of carbon dioxide and water produced is measured, and from this data, the amount of carbon and hydrogen in the original compound can be calculated.

3. To calculate the mass percent of each element in the original compound, the mass of the element in the sample is divided by the total mass of the sample and multiplied by 100.

4. The mass percent of oxygen in the original compound can be calculated by subtracting the mass percent of carbon, hydrogen, and nitrogen (if present) from 100%.

5. The empirical formula of the compound can be determined from the mass percent of each element.

6. To determine the molecular formula of the compound, the empirical formula mass is calculated and compared to the experimental molar mass of the compound.

7. Combustion analysis can also be used to determine the calorific value of a compound, which is the amount of heat energy released when the compound is burned.