Solution

The reaction is an exothermic reaction. Heat is given off.

The calibration factor of the calorimeter is given by the expression below.

Obtain the amount of energy released from 0.02134 grams of ethene burnt in oxygen according the equation below

Calibration factor X change in temperature = 759.6 X 1.42 = 1.078KJ

The enthalpy change is energy/mol

SO!

Step 1) Mole of ethene added = 0.02134 /28 = 0.00076 mole

Step 2) Divide the amount of energy by the number of mole of ethene.

1.078 / 0.00076 = -1418.42Kj/mol

Note how the enthalpy change has a negative sign. This indicates an exothermic reaction (heat given out).

Click to hide the solution