Question

When converting work to kilojoules, what is the conversion factor recalled?

a. 1 kcal = 2.184 kJ
b. 1 kcal = 4.184 kJ
c. 1 kcal = 6.184 kJ
d. 1 kcal = 8.184 kJ

Answer 1

To convert kilocalories to kilojoules, the conversion factor 1 kcal = 4.184 kJ is used.

Step-by-step explanation:

When converting work from kilocalories to kilojoules, the correct conversion factor to recall is 1 kcal = 4.184 kJ. Thus, option b. 1 kcal = 4.184 kJ is the correct answer. This equivalence is used because 1 food calorie (which is actually 1 kilocalorie or 1 kcal) is defined as the amount of energy it takes to heat one kilogram of water by 1°C, which equals 4184 joules. In energy terms, 1 cal = 4.184 J, and therefore 1 kcal = 1000 cal = 4184 J.