Question

If an unknown piece of food produced 25 Cal of heat in a calorimetry test and lost 5 grams of mass after burning, how many Calories are there in 1 gram of that food?

a) 1 Cal/g
b) 5 Cal/g
c) 25 Cal/g
d) 30 Cal/g

Answer 1

The caloric content of the unknown food sample in the calorimetry test is 5 Calories per gram, calculated by dividing the total Calories produced by the mass lost. The procedure illustrates the use of bomb calorimetry to determine energy content in foods.

Step-by-step explanation:

To calculate the number of Calories per gram of the unknown food sample from a calorimetry test, we use the given data: 25 Calories of heat were produced, and the sample lost 5 grams of mass after burning. Using this information, we simply divide the total number of Calories by the mass of food burned to get the caloric content per gram.

The calculation is as follows: 25 Cal ÷ 5 g = 5 Cal/g. So, the caloric content of the food sample is 5 Calories per gram.

This method is based on bomb calorimetry, a technique wherein a food sample is combusted in a sealed container surrounded by water. The heat transferred to the water from the burning food is then measured, indicating the energy content of the food. This method was historically used to measure the caloric value of foods, but today caloric content is often calculated from the macronutrients present such as proteins, carbohydrates, and fats.