A student wants to compare the energy content of different dried food samples.
Describe how a student could carry out a simple laboratory experiment to determine and compare the energy content of different dried food samples (such as croutons or dried fruit).
In one test, a student burned a 1.5 g1.5\text{ g}1.5 g sample of a crouton to heat 25 cm325\text{ cm}^325 cm3 of water. The temperature of the water increased from 18∘C18^\circ\text{C}18∘C to 46∘C46^\circ\text{C}46∘C.
Calculate the energy released per gram of this food sample in Joules per gram (J/g\text{J/g}J/g). Directly apply the formula:
Energy released (J)=mass of water (g)×4.2×temperature rise (∘C) \text{Energy released (J)} = \text{mass of water (g)} \times 4.2 \times \text{temperature rise (}^\circ\text{C)} Energy released (J)=mass of water (g)×4.2×temperature rise (∘C)Assume 1 cm31\text{ cm}^31 cm3 of water has a mass of 1 g1\text{ g}1 g. Show your working.
65 exam-style questions on Edexcel IGCSE Biology Nutrition. Each one has a worked solution and a mark scheme showing where the marks go.