Video Transcript
The chemical equation for the combustion of glucose is shown. C6H12O6 solid plus six O2 gas react to produce six CO2 gas plus six H2O liquid plus 2,808 kilojoules. How much energy is released when 2.5 moles of glucose are burned?
Combustion is burning. It involves reaction with oxygen. Since the equation shows the combustion of glucose and we know O2 to be oxygen, then C6H12O6 must be glucose. We can see from this equation that one mole of glucose reacts with six moles of oxygen to produce six moles of CO2 or carbon dioxide and six moles of H2O or water. 2,808 kilojoules of energy are also produced. Since the energy is written as a product, this indicates that energy is released during this reaction.
We have found out from the equation that 2,808 kilojoules of energy is released when one mole of glucose is burned. The amount of energy released is directly proportional to the number of moles of glucose. If we had doubled the amount of glucose, which is two moles of glucose, and doubled the amount of oxygen, we would get double the amount of products and double the amount of energy.
The question asks us how much energy is released when 2.5 moles of glucose are burned. To go from one mole to 2.5 moles, we have to multiply by 2.5. Since the amount of energy released is proportional to the number of moles of glucose, we can multiply the amount of energy by 2.5 to work out how much energy is released when 2.5 moles of glucose are burned. If we multiply 2,808 kilojoules by 2.5, we get 7,020 kilojoules.
So, the answer to the question “How much energy is released when 2.5 moles of glucose are burned” is 7,020 kilojoules.
