Question

Calculate the kilocalories for each of the following: one cup of popcorn that produces 141 kJ when burned in a calorimeter?

Answer 1

To convert the energy produced by burning one cup of popcorn from kilojoules to kilocalories, divide 141 kJ by the conversion factor of 4.184 to get calories, then divide by 1,000 to obtain 0.03371 kilocalories.

Step-by-step explanation:

To calculate the kilocalories for one cup of popcorn from the given 141 kJ (kilojoules) of energy it produces when burned, you can use the conversion factor that 1 calorie is equivalent to 4.184 kilojoules. Therefore, to convert kilojoules to kilocalories, you can follow these steps:

1. First, convert kilojoules (kJ) to calories by dividing the energy value in kJ by the conversion factor 4.184.
2. Next, convert calories to kilocalories by dividing the number of calories by 1,000 since there are 1,000 calories in one kilocalorie.

In mathematical terms, this means:

(141 kJ / 4.184 kJ/cal) / 1,000 = 33.71 calories or 0.03371 kilocalories.

Remember that dietary calories are often referred to as Cal with a capital 'C', which are actually kilocalories; hence, one cup of popcorn provides approximately 0.034 Cal (or kilocalories).