Question

A 0.50-g sample of vegetable oil is placed in a calorimeter. when the sample is burned, 18.9 kj is given off. what is the energy value (kcal/g) for the oil?

Answer 1

First of all, we need to convert the energy produced from kilojoules to calories. 1 kJ corresponds to 239.1 cal, therefore:

$E=18.9 kJ \cdot 239.1 =4519.4 cal$

And so now we can calculate the energy value of the oil:

$E_v = \frac{E}{m}=\frac{4519.4 cal}{0.50 g}=9038.8 cal/g$