1. ENTHALPY OF FORMATION: Combustion of Methanol
River Dell High School
Team A
Jason Anesini
Alina Kim
Jae Noh

2. PURPOSE
To construct an alcohol/hydrocarbon-fueled combustion reactor that propels a stopper upwards
To determine the optimal way of measuring the energy released in the combustion reaction
To determine the enthalpy of formation of methanol

3. EVERYDAY COMBUSTION
Fireworks
Charcoal
Car engines
Gasoline

4. COMBUSTION What is combustion? CH3OH(l) + 3/2O2(g)  CO2(g) + 2H2O(g)
Exothermic Reaction
Endothermic Reaction
Energy released
∆Hp < ∆Hr
-∆Hrxn
Energy absorbed
∆Hr < ∆Hp
+∆Hrxn

5. EXOTHERMIC VS. ENDOTHERMIC

6. ENTHALPY Heat of formation Heat of combustion
∆H when one mole of a compound is formed from its elements
Standard heat of formation
Heat of combustion
Heat released in a combustion reaction

7. METHANOL STRUCTURE

8. METHANOL Synthesized from CO and H2
Used as energy source and in many everyday appliances
Lowest Ea among alcohols
Costs 3x less than ethanol
Memorize everyday supplies

9. EXPERIMENT APPARATUS Stopper – with green line
Methanol (stored in Drierite)
Nalgene bottle (500 mL)
Insulation
Bubble wrap
Glass fiber
Tesla coil
Copper wires
Drierite is anhydrous calcium sulfate (check)
Goes from blue to white (hydrous state)

10. EXPERIMENT APPARATUS Rubber Stopper Tesla Coil Methanol and Drierite
Nalgene Bottle (500mL)

11. MEASUREMENT APPARATUS
120 f.p.s camera (Sony HDR-SR11)
Meter stick
Thermometer
Laptop
Temperature probe
Vernier Software: Logger Pro 3.8.4

12. KINETIC ENERGY E = 1/2mv2 Mass of cork (w/ line) before reaction
Film: observe frame-by-frame to find initial velocity

13. KINETIC ENERGY
Frame 987
Frame 988

14. HEAT ENERGY q = mCp∆T Variable Air in Bottle Bottle Mass
Volume of bottle and density of air
Mass of bottle (without copper wires and insulation)
Specific Heat (Cp)
At the average temperature of 300C
Specific heat of LDPE
Temperature Change (∆T)
Thermometer
Temperature probe (laptop)
Separately discuss insulation if necessary

15. RESULTS Total energy: kinetic energy & heat energy
Cork
Air in bottle
Bottle
Heat energy represented the majority of total energy
Equations in appendix were imported into Excel to make the spreadsheet

16. DATA TABLE

17. DATA ANALYSIS Experimental ∆Hf of methanol: -535kJ/mol
Theoretical ∆Hf of methanol: kJ/mol
124% error
Small ∆Hc results in large experimental ∆Hf
ΔHc = [ΔHf (CO) + 2ΔHf (H20)] – [ΔHf (CH3OH)]
Experimental ∆Hf is “more” than theoretical because experimental heat of combustion is low (“inverse relationship”)

18. COMPLETE VS. INCOMPLETE COMBUSTION
Characteristic
Complete Combustion
Incomplete Combustion
Limiting Reagent
Methanol
Oxygen gas
Formula
CH3OH + 3/2O2  CO2 + 2H2O
CH3OH + O2  CO + 2H2O
Products
Carbon dioxide gas
Carbon monoxide gas (poisonous)

19. ADDRESSED PROBLEMS Assumption that total energy transferred to cork
Bottle warm to the touch after reaction
Insulation to reduce heat loss to environment
Limiting reagent of reaction
Volume of methanol used (0.4 mL)

20. CONCLUSION Energy not accounted for
Energy escaped from bottle
Multiple revisions to the procedure
In the future…
Made revision to get to where we are, in the future….blahblahblah
-insulated container
-low thermal conductivity

21. WORKS CITED
Slide 3 – Fireworks (accessed May 8, 2013).
Slide 3 – Car Engine (accessed May 8, 2013).
Slide 5 – Exothermic and Endothermic Reactions (accessed May 8, 2013).
Slide 7 – Methanol Structure. (accessed May 8, 2013).
Slide 7 – Methanol Ball-and-Stick Model. (accessed May 8, 2013).

22. TESLA COIL
Tesla coils contain a transformer that changes low voltage to high voltage
Increases the voltage and frequency
When the electrode gets near another surface it discharges onto that surface

23. Incomplete Combustion
Assumption: methanol would combust in complete combustion
After experiment: methanol combusted in incomplete combustion
Refer to Calculations XII & XIII in Appendix: Part 1