Abomb calorimetric experiment was run to determine the enthalpy of combustion of methanol. the reaction is ch3oh(l)+3/2o2(g)→co2(g)+2h2o(l) the bomb calorimeter has a heat capacity of 250.0 j/k. burning 0.028 g of methanol resulted in a rise in temperature from 21.50 ∘c to 23.41 ∘c. calculate the change in internal energy for the combustion of methanol in kj/mol.

The change in internal energy during the combustion reaction is- 545.71 kJ/mol.

Explanation:

First we have to calculate the heat gained by the calorimeter.

where,

q = heat gained = ?

c = specific heat =

= Initial temperature =

= Final temperature =

Now put all the given values in the above formula, we get:

Now we have to calculate the enthalpy change during the reaction.

where,

= enthalpy change = ?

q = heat gained = -477.5 J

n = number of moles methanol =

Therefore, the change in internal energy during the combustion reaction is- 545.71 kJ/mol.

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