Corn makes up a large proportion of people’s diet in some parts of the world - VCE - SSCE Chemistry - Question 6 - 2022 - Paper 1

To calculate the energy content from the macronutrients, we use the general energy values for each:

• Proteins provide approximately 17 kJ/g.
• Fats provide approximately 37 kJ/g.
• Carbohydrates provide approximately 17 kJ/g.

Using the average quantities from Table 1:

1. Protein:

   • Energy from Protein = 10.7 g × 17 kJ/g = 181.9 kJ

2. Fat:

   • Energy from Fat = 5.0 g × 37 kJ/g = 185 kJ

3. Carbohydrates:

   • Energy from Carbohydrates = 78.7 g × 17 kJ/g = 1337.9 kJ

Now, sum the energy contributions:

Total Energy = 181.9 kJ + 185 kJ + 1337.9 kJ = 1704.8 kJ

Since this is for 100 g of popcorn, to find the energy per gram, divide by 100:

Energy per gram = 1704.8 kJ / 100 = 17.048 kJ/g.

Thus, the energy content of air-popped popcorn is approximately 17.05 kJ/g.