Ethanol is increasingly being used as a fuel for cars.

The standard enthalpy change of formation of carbon dioxide is - 393 kJmol.

The standard enthalpy change of formation of water is - -286 kJmol.

The standard enthalpy change of formation of ethanol is - 277 kJmol.

What is the standard enthalpy change of combustion of ethanol?

= - 522.5/,/, kJmol^{-1}

Explanation:

Firstly, we know that 0.36 g of ethanol burned, so we can convert this into a number of moles.

Using a formula triangle to calculate the number of moles of ethanol in a 0.36 gram sample

Secondly, we can use / Delta H=cm/Delta T to calculate the enthalpy change in the experiment described in the question (ie when 0.008 moles of ethanol is burned).

/Delta H=cm/Delta T = 4.18 x 0.2 x 5

= 4.18 kJ

Lastly, we can use the enthalpy change for the experiment in the question to calculate the enthalpy of combustion (ie when one mole of ethanol is burned).

0.008/,/, moles/,/, ethanol = 4.18kJ

1/,/, mole/,/, ethanol = / frac{1}{0.008} / times 4.18

= - 522.5/,/, kJmol^{-1}

-522.5

Explanation:

because for the formula i found that.