Demonstration Lesson Plans Click Below ! ! :
3. Absorption of Heat & Non-Burning Paper Cup
4. The Non-Burning Dollar Bill
5. Reaction Rates & the "Grain Elevator Explosion"
6. Reaction Rates & the
"Light Stick"
Section 1- Chemical
& Physical Changes
Section 2- Chemical
& Physical Properties
Section 3 - Water &
Its Properties
Section 4 - Corrosion
Section 5 - Acids/Bases/In dicators
Section 6 - Gases & Pressure
Appendix 1 -Charts & tables, Disposal of Chemicals, Sources of Chemicals, Preparations of Acid and Solutions
Appendix 2 Properties of Common Elements, Descriptions of the Elements, Ban Dihydrogen Monoxide
Appendix 3 Principles of Education, Prof. Hanko
The Reformed Witness, Rev. Cammenga
SECTION 1 : CHEMICAL AND PHYSICAL CHANGES
Absorption of Heat and the "Non-Burning Cup"
Chemical Concept or Topic: -
- Combustion
- Heat absorption
- Water properties
Materials: -
- Flame, Bunsen burner or candle
- Paper cup
- Water
Procedure:
The goal of this demonstration is to show the student that in order for something to burn it needs to reach a specific temperature. Paper ignites and burns at 451 o F. (One could at this time bring up the book Fahrenheit 451 by Ray Bradbury).
- Obtain a paper cup (or make your own). Place it above a flame and observe.
- Obtain a paper cup (or make your own) and fill it with water. Place it above a flame and observe.
Questions:
- Does the paper cup ignite when it has water in it? Why not?
- What property of water is important in this demonstration, as it is the water, which prevents the cup from igniting?
Explanations:
- The paper cup, which is empty immediately, ignites when it is placed above the flame.
- The paper cup, which is filled with water, does not ignite when it is placed above the flame. The reason for this difference is attributed to the presence of the water. The water absorbs the heat given off by the flame. It absorbs so much heat that the paper can not achieve the temperature necessary for it to ignite. If left long enough above the flame, the water in the cup could boil and yet the cup would not ignite. As long as the paper, which is in contact with the flame, has water touching it, it will not ignite. This is because of the tremendous amount of heat that a molecule of water can absorb.
- The heat capacity (or ability to hold heat) is the property of water that is so important in this demonstration. Water can absorb 4.184 J of energy per degree Celsius per gram of water. That is; if one had one gram of water and raised the temperature of that water by one degree Celsius, then it is said that the water will have absorbed 4.184 J of energy. This demonstration further emphasizes the fact that things can not burn unless they reach their "critical" temperature.
One sees God’s providential hand at work here too. God ordained and now governs even the properties of water so that lakes absorb much heat and have a "moderating effect" on climate. We are reminded here again of a purpose of water. Water, in Scripture, is preserving and destructive in nature. God saved His people with the Flood, and destroyed the world with the same Flood. God saved His people by having them walk through the Red Sea on dry ground, and destroyed obstinate Pharaoh and all his host in that same Red Sea. When we observe the properties of water in Creation, such as, that water absorbs heat energy and "preserves" the paper cup from burning we are reminded of how God used water in the Old Testament. This study of water reminds us of God’s workings in history, of His preservation of His people and of His destruction of the wicked. May we be reminded of these things and give God all glory and honor as we study these things in Science.
Reference: Woodrow Wilson Conference. Grand Valley State University. Allendale, MI: 1991.
The Federation Board of the Protestant Reformed Christian Schools commissioned Joel Minderhoud to develop this Repertoire of Chemical Demonstrations
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