Question

one cup of clam chowder contains 16g of carbohydrate, 12g of fat, and 9g of protein. how much energy, in kilocalories and kilojoules, is in the clam chowder? (round off the kilocalories or kilojoules to the tens place)

Answer 1

enthalpies of combustion for fat = -39kj/g

carbohydrate = -16kj/g

protein -23kj/g,

here

12g = fat, 16 g = carbs, and 9 g = protein.

Total enery from fat = 12.0 g* -39kj/g

= -468 KJ

Total enery from carbohydrate = 16 g* -16 kj/g

=- 256 KJ

Total enery from protein = 9.0 g* -23 kj/g

=- 207 KJ

Total enegy = -468 KJ +(- 256 KJ) + (- 207 KJ) = -931 KJ

there are 4.18 joules in one scientific calorie

1.00 scientific calorie = 4.18 J

931000 J *1.00 scientific calorie / 4.18 J = 2.2*10^5 scientific calorie