Express your answer to two significant figures and include the appropriate units

ID: 706475 • Letter: E

Question

Express your answer to two significant figures and include the appropriate units:

a) the total kilojoules in two tablespoons of crunchy peanut butter that contains 1 g of carbohydrate, 14 g of fat, and 7 g of protein

b) the grams of protein in one cup of soup that has 140 kcalwith 8 g of carbohydrate and 6 g of fat

c) the kilocalories in one can of cola if it has 30. g of carbohydrate and no fat or protein

d) the total kilocalories for a diet that consists of 57 g of carbohydrate, 8 g of fat, and 130 g of protein

Ans :

a) 1 g of carbohydrates = 17 KJ

1 g of protein = 17 KJ

1 g of fat = 37 KJ

So here , the kilojoules in peanut butter :

= 1(17) + 14(37) + 7(17)

= 650 KJ

b) 1 g of protein = 4 Kcal

1 g of carbohydrate = 4 kcal

1 g of fat = 9 kcal

Now let us assume that the protein here is m grams

So now :

140 = m(4) + 8(4) + 6(9)

140 = 4m + 86

m = 14 grams

So the mass of protein = 14 g

c) Each gram of carbohydrate gives 4 kilocalories

So 30.g carbohydrate = 30. x 4

= 120 g

d) The number of kilocalories :

= 57(4) + 8(9) + 130(4)

= 820 kcal

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.