Chemistry
Unit 3
Name ________________________
Period ___ Date _______________
Food Lab
Purpose: The purpose of this lab is to use water’s specific heat and combustion (burning) to determine
the energy given off by a fuel source
Test Tube with holder
Materials: One small test tube
Fuel Source (potato chip, wood splint, etc)
10 mL graduated cylinder
5 mL distilled water
thermometer
METAL test tube rack
test tube holder
Rack
Figure 1A
Fuel
Procedure:
1.
2.
3.
4.
5.
Put 5 mL of water in the test tube and set up as shown in Figure 1A above
Calculate the mass of the water heated (hint: water’s density is 1 g/mL) & record as “A”
Insert the thermometer in the water to determine the initial water temperature
Determine the mass of the fuel to the nearest .1 gram
Place the fuel source as close to the bottom of the test tube as possible (without
smothering) then ignite the fuel
6. Once the fuel extinguishes, determine the temperature increase of the water due to
warming by the fuel source & record as “B”
7. Calculate the heat of combustion below using the specific heat of water (4.18 J / g * oC)
H.O.C. of fuel (due to water’s temp. rise) = 4.18 Joules/g*oC x “A” grams x “B” degrees
Show Calculation here:
Data Table:
A. Mass of Water
Initial Temperature of Water
Final Temperature of Water
B. Temperature Increase
C. Mass of Fuel
Questions:
1. How much energy is produced from the combustion of your fuel?
2. The H.O.C. of methane (natural gas) is 55.6 kJ/g, how does the combustion of your fuel source
compare? Is this a better fuel or worse? Why?
3. One food calorie (Calorie) = 4.184 kJ of energy. How many Calories does your fuel generate?
4. Complete the energy bar charts for the heat of combustion of food using the water.
5. Draw particle diagrams showing the arrangement and motion of the water before and after the
combustion of the food.
6. Sketch the heating curve for the water.