Chemistry question help pleaseeeeeee (1 Viewer)

[littlesmallworld]

One way of minimising the greenhouse effect is to minimise the amount of carbon dioxide formed per kilojoule of energy produced. Arrange the following fuels in order of increasing amount of carbon dioxide per kilojoule of energy released. For each substance the amount of energy released in kJ per mole during combustion is given in brackets: coal, CH (455); methanol, CH3OH (726); octane (petrol), C8H18 (5460); ethanol, C2H5OH (1360); 1-propanol, C3H7OH (2021); methane (890)

 

[anomalousdecay]

You need to find how many kilojoule's of energy are released and how many moles of carbon dioxide are produced.

To do this, you must write a balanced chemical equation for each reaction. For example, with Octane:



Now, for every mole of Octane used, 5460 kilojoule's of energy is released.

For this reaction, 8 times as many moles of carbon dioxide are released as Octane produced.

This means that to get the energy released for the production of carbon dioxide we can deduce that:



What we need is the moles of carbon dioxide released per kilojoule of energy.

Hence, you inverse the value obtained to get:




Then you obtain the answers for all the other fuels and order them from lowest value to the highest value.

When you do this, you can deduce that the fuel during combustion that produces the least carbon dioxide is the one with the lowest value. You can also deduce that the fuel with the highest value produces the most carbon dioxide during combustion.

 

[strawberrye]

These questions are not particularly hard, but you need to develop the patience to work through each part step by step