Question

A chemical reaction gives off 1,500 kJ of heat energy. About how many calories is this? (1 calorie = 4.18 Joules)

Answer 1

First you need to convert kiloJoules to Joules

1 kJ is 1000 J

1500kJ *1000J == 1500000 J
Then 1500000J * 1Cal/4.18 J == 358851.6746 calories

Answer 2

Answer : The heat energy in calorie is
`3.59* 10^5\text{ Calorie}`

Explanation :

As we are given the conversion for heat energy.

`1\text{ Calorie}=4.18\text{ Joules}`

or,

`1\text{ Joules}=(1)/(4.18)\text{ Calorie}`

As we are given that:

Heat energy in kJ = 1500 kJ = 1500000 J

conversion used : (1 kJ = 1000 J)

Now we have to determine the heat energy in calorie.

As,
`1\text{ Joules}=(1)/(4.18)\text{ Calorie}`

So,
`1500000\text{ Joules}=\frac{1500000\text{ Joules}}{4.18\text{ Joules}}\text{ Calorie}=3.59* 10^5\text{ Calorie}`

Therefore, the heat energy in calorie is
`3.59* 10^5\text{ Calorie}`