H H
| |
H-C-C-O-H O=O H-O-H
| | O=C=O
H H + + H-O-H
O=O
O=C=O H-O-H
O=O
Bond Breaking Values
Bond Creating Values
4728
6004
-1276
The reaction is exothermic by. 1276 kJ
Word Equation
Propanol + oxygen carbon dioxide + water
Molecular Equation
2C (3) H (7) OH + 9O(2) 6CO(2)+ 8H(2) O
Structural Equation
H H H O=O H-O-H
| | | O=C=O
H-C-C-C-O-H O=O H-O-H
| | | O=C=O
H H H O=O H-O-H
+ O=C=O +
H H H O=O H-O-H
| | | O=C=O
H-C-C-C-O-H O=O H-O-H
| | | O=C=O
H H H O=O H-O-H O=C=O
O=O H-O-H
O=O H-O-H
O=O
Bond Breaking Values
Bond Creating Values
12832
17084
- 4252
The reaction is exothermic by . 4252 kJ
Word Equation
Butanol + oxygen carbon dioxide + water
Molecular Equation
C (4) H (9) OH + 6O(2) 4CO(2)+ 5H(2) O
Structural Equation
H H H H O=O H-O-H
| | | | O=C=O
H-C-C-C-C-O-H O=O H-O-H
| | | | O=C=O
H H H H + O=O + H-O-H
O=C=O
O=O H-O-H
O=C=O
O=O H-O-H
O=O
Bond Breaking Values
Bond Creating Values
8568
11080
-2512
The reaction is exothermic by. 2512 kJ
According to my Calculations Propanol produces, the most energy theoretically, some energy may be lost as light or in incomplete combustion.
Plan
To carry out the investigation I will need the Following Apparatus
- Electronic Balance
- Stand
- 1 Beaker with 100mls of water
- 1 thermometer
- 1 Tripod with claypipe triangle (instead of wire gauze)
- 4 spirit Burners (1 Methanol 1 Ethanol 1 Propanol 1 Butanol)
- 3 Ceramic Mats (2 to shield the flame 1 to use as a base)
-
1 Bunsen Burner
-
Splints
Diagram
I will set up the apparatus as shown above and after weighing the spirit Burners and noting the weight. I will light the spirit burner and then Monitor the temperature until it rises 20 C at which point the flame will be extinguished. I will then weigh the spirit Burner and calculate the total amount of alcohol lost in that period of burning. This will then be repeated for a second and possibly third Result before moving to a different alcohol.
Fair Test
To make this a fair test I will weigh the spirit Burners accurately before & after the Period of Burning. I will use Ceramic mats to stop any Drafts from diverting any heat from the beaker. I will also keep the amount of water at 100 ml. I will keep the beaker clean so, as any carbon (from any incomplete combustion) does not absorb any more heat. If the flame goes out for any reason other then the end of that part of the investigation, that part of the investigation will start again.
Safety
The flames will not be touched & safety specs will always be worn at all times. Any burns/scolds will be reported to the teacher and any appropriate medical action will be taken
Flames will be extinguished using the caps of the spirit Burners.
Results
These results show that Propanol produces the most heat on burning as it loses the least amount of fuel after heating the water.
Graph
Conclusion
My results show that as predicted Propanol gives the most heat on burning. My results also show that methanol produced the worst amount of heat on burning this result was unexpected as ethanol was predicted to be the most inefficient alcohol. This may have been because of incomplete combustion.
Evaluation
My predictions where not entirely accurate because out of the total energy lost part of that would be in the release of energy in the form of light or incomplete combustion. To make this experiment more reliable I would put the apparatus in an controlled environment where any drafts or the moisture in the air could affect it (moisture may absorb some of the heat given off)
