Question

Determine the total kilojoules in two tablespoons of crunchy peanut butter that contains 6 g of carbohydrate, 11 g of fat, and 9 g of protein.

Answer 1

Answer:

  665 kJ

Explanation:

We assume that carbohydrates and protein each have 4 kilocalories per gram, and that fat has 9 kilocalories per gram. Then the number of kilocalories in the peanut butter is ...

  4(6 +9) +9(11) = 159 . . . . kilocalories

Each kilocalorie translates to 4.184 kilojoules, so the total is ...

  (159 kCal)(4.184 kJ/kCal) = 665.256 kJ

2 Tbsp of crunchy peanut butter contains about 665 kJ of energy.