Answer: 878 kJ of energy is there in cheeseburger
Explanation:
Given : calorific value of fat = 38kJ/g
calorific value of carbohydrate = 17 kJ/g
calorific value of protein = 17kJ/g
1 g of fat contains energy = 38 kJ
7.0 g of fat contains energy = ![\frac{38}{1}\times 7.0=266 kJ](https://tex.z-dn.net/?f=%5Cfrac%7B38%7D%7B1%7D%5Ctimes%207.0%3D266%20kJ)
1 g of carbohydrate contains energy = 17 kJ
25 g of fat contains energy = ![\frac{17}{1}\times 25=425kJ](https://tex.z-dn.net/?f=%5Cfrac%7B17%7D%7B1%7D%5Ctimes%2025%3D425kJ)
1 g of protein contains energy = 17 kJ
11 g of protein contains energy = ![\frac{17}{1}\times 11=187kJ](https://tex.z-dn.net/?f=%5Cfrac%7B17%7D%7B1%7D%5Ctimes%2011%3D187kJ)
Total energy = (266+425+187) kJ = 878 kJ
Percentage O: 69.54
Percentage N: 30.46
Dividing each percentage by the components molecular weight:
Oxygen: 69.54 / 16 = 4.35
Nitrogen: 30.46 / 14 = 2.18
Ratio of nitrogen to oxygen = 1 : 2
Empircal formula: NO₂
Mass of empirical formula = 46
Repeat units = 92 / 46 = 2
Molecular formula = N₂O₄
0.25 g al should equal around 0.009265594867125 moles
I hope this help