Producing required energy from Combusting Methane

[krayziemuzick]

Homework Statement

How much methane, CH4 is must be burned to produce 6.38x10^6j of energy

Homework Equations

CH4 + 3O2 --> CO2 + 2H2O

The Attempt at a Solution

This is actually the second part of a pretty long multi part question. I couldn't find out how to figure out the amount of energy produced by this reaction. In the first part of the question I found how how much energy was required to raise 5.8x10^5 grams of air (specific heat of 1.1 j/(gxC) by 10C. Which is where I get the energy from. Could anyone please guide me as to where to start? I have been looking in my book but have not found anything.

 

[Borek]

You need enthalpy of methane combustion. It is either given somewhere in the question, or can be calculated from the previous data, or there are tables in your book, where this information is listed.

 

[Blueshift5]

To calculate the amount of methane needed to produce 6.38x10^6 joules of energy, we first need to determine the amount of energy produced by the combustion of one mole of methane. This can be done by using the enthalpy of formation of methane, which is -74.8 kJ/mol. This means that for every mole of methane combusted, 74.8 kJ of energy is released.

Next, we need to convert the given energy of 6.38x10^6 joules into kJ, which is 6380 kJ. Now, using the conversion factor of 74.8 kJ/mol, we can set up a proportion to find the number of moles of methane needed:

6380 kJ/1 mol = 74.8 kJ/x mol

Cross-multiplying and solving for x, we get:

x = 6380 kJ * 1 mol/74.8 kJ
x = 85.37 moles of methane

Therefore, 85.37 moles of methane must be burned to produce 6.38x10^6 joules of energy. This can also be converted into grams by using the molar mass of methane, which is 16.04 g/mol. This means that the mass of methane needed is 85.37 moles * 16.04 g/mol = 1369.25 grams. So, approximately 1369.25 grams of methane must be burned to produce 6.38x10^6 joules of energy.