Question

a 2.5 g sample of french fries is placed in a calorimeter with 500z0g of water at an intial temperture of 21 degrees celcius agter combustion of the frnech fries the water has a temperature of 48 degrees celcius. what us rhe caloric calue (kcal/g) of the french fries

Answer 1

To find the caloric value (energy content) of the French fries, you can use the concept of calorimetry. The energy released by the combustion of the French fries will be absorbed by the water in the calorimeter. The formula to calculate the caloric value is:

Caloric Value = (Energy Absorbed by Water) / (Mass of French Fries)

First, calculate the energy absorbed by the water using the specific heat formula:

Energy = (Mass of Water) * (Specific Heat of Water) * (Change in Temperature)

Given:

- Mass of water (m) = 500 g

- Specific heat of water (C) = 1 cal/g°C

- Initial temperature (T1) = 21°C

- Final temperature (T2) = 48°C

Energy = (500 g) * (1 cal/g°C) * (48°C - 21°C) = 13500 cal

Now, calculate the caloric value of the French fries:

Caloric Value = (Energy Absorbed by Water) / (Mass of French Fries)

Caloric Value = (13500 cal) / (2.5 g) = 5400 cal/g

To convert cal/g to kcal/g, divide by 1000 (since 1 kcal = 1000 cal):

Caloric Value = 5400 cal/g / 1000 = 5.4 kcal/g

So, the caloric value of the French fries is approximately 5.4 kcal/g.