Purpose:Have you ever wondered why some foods give you more energy than others?

Background Information:Calorimetry is the study of

finding the amount of energy in a material.

Title: Calorimetry Lab

Basic combustion calorimeter:

How calorimeters work:1. The sample is placed in a small metal container and lit, or combusted, so it burns up. 2. The heat from the sample is transferred to the can and then to the water. 3. The temperature difference of the water is measured from start to finish. A larger temperature difference means that more energy was transferred.

In food, intrinsic energy is measured in Calories, with a capital C. A Calorie equals 1000 calories, with a lower case c (aka… kilocalorie). We “count” nutritional calories in 1000’s – lower case “c” calorie.

A calorie is the amount of energy it takes to heat 1 gram of water 1 degree Celsius.

Hypothesize:

1. Which snack item contains the least calories per unit?

2. Which snack item contains the most calories per unit?

Let’s share, what did you hypothesize?

What is the equation for calculating heat energy absorbed or released?

q = c x m x ΔTWhat is the specific heat (c) of water?

c = 4.184 J/(g·°C)What is the mass (m) of water we are using?

volume = 50ml, so m = 50g

What is the equation for calculating the change in temperature (ΔT)?

ΔT = Tf – Ti Ti = initial temperature

Tf = final temperature

So our equation for each snack will be…q = 4.184 x 50 x ΔT