Investigation of Liquid Combustion
Introduction
In this experiment, we will find out why some liquids burn at certain temperatures.
Risk assessment
Due to the fact that we are dealing with fire, long hair must be tried back goggles warn and lab coats on. There was also a risk of that somebody could bur themselves or set alight an object. In addition, if we were to pick up a hot crucible without gloves we must use appropriate equipment so that we do not burn our hands.
Materials
- Crucible
- Heat proof mat
- Bunson Burner
- Tongs
- Splint
- String
- 1cm3 of kerosene
- 1cm3 of petroleum spirit.
Method
Petroleum (1cm3) was placed into a crucible and was then ignited using a lighted split. Once we lighted the petroleum and it had a burned we then poured 1cm3 of kerosene and attempted to ignite it using a lighted splint. After you have tried to light the kerosene with just a lighted splint place about 2-3 cm length of string into the crucible so that it is partly dipping into the liquid. Note the appearance how the kerosene lit.
Results
Petrol- The flame was quite tall and was yellow. The petrol ignited very quickly and there was soot around the edges of the crucible. When the petrol have burned the flame go smaller until it went out by itself.
Kerosene- The Kerosene did not light so therefore there was no flame.
Kerosene with string- The string slowly burnt away until it reached the crucible with the kerosene in which then ignited. It burnt with a tall, large yellow flame and left a lot of soot in the crucible when it had all burnt.
Evaluation
The experiments purpose was to investigate why certain liquids burn at different temperatures. By burning the petrol it showed us that it had, a low flash point so would ignite and burn easily. The kerosene by it selves did not burn meaning it have a high flash point, meaning it needs high temperatures to ignite and burn. Both the petrol and kerosene produced soot showing full combustion.
Conclusion
In conclusion, the petrol was the easiest ignite and could start a fire very easily while the kerosene did not light with just a lighted splint. It has a high flash temperature that why it is used as aeroplane fuel.
Investigation of flames
Introduction
In this experiment we will be investigating how long it takes for a piece of paper to burn when lit from the top corner and the bottom corner.
Risk Assessment
Due to the fact that we are dealing with fire, long hair must be tried back goggles warn and lab coats on. There was also a risk of that somebody could burn themselves or set alight an object.
Materials
- 2 sheets of A4 paper
- Heat proof mat
- Stands and Clamps
- Bunson Burner
- Splint
- Timer
- 2 sheets of A4 paper
Method
First we attached the clamps to the stands, and then attached a piece of A4 paper. We then lit the top of the short edge in the middle. It was then timed how long the piece of paper took to burn away completely and the time recorded. The experiment was then repeated with another piece of paper but lit at the bottom edge. Again it was timed until the paper was completely burned away and the time recorded.
The Results
`1st Paper: It started to burn instantly and spread downwards. The paper then dropped out of the clamps and fell to the table but it was not all burnt. After a while it all burnt out at 2 minutes and 11 seconds.
2nd Paper:. : It started to burn instantly and spread downwards. The paper then dropped out of the clamps and fell to the table but it was not all burnt. After a while it all burnt out at 23.43 seconds.
Evaluation
For paper 1 to burn it took 2 minutes and 11 seconds. The second piece which only took 23.43 seconds. For the first piece of paper it took longer to completely burn away because it was lit at the top of the paper. This is due to that most of the heat that was produced by the burning paper was lost above it. The second piece of paper burnt easier than the first because fire spreads more rapidly upwards rather than downwards. This is why is a fire starts at the bottom of something it spreads quicker as flames spread up.
Task 2 (M1)
To start a fire there has to be an ignition source. Possible sources could be faulty wires rubbing together causing friction and getting hot enough to start the fire, overloaded plugs and oil lamps etc. Some other sources could be cigarettes. They may not have been put out properly, matches and gas lighter. Another source could be computer/ other electrical items. If they are left on for a long period, they will become hot and possible trigger a fire. Christmas lights can also play a part in a ignition of a fire because they are also normally on for a long period causing the Christmas tree to become how and burst into flames. Items in the kitchen like ovens, kettles, chip fryers etc also have heat coming from them. If they are not working properly, they will also become a source of ignition. A drink placed near a electrical item can also start a fire. Lastly, arson could be an ignition source. If somebody wanted to have a financial gain, they could start the fire their self.
Task 3 (D1)
From studying the text I was given the main causes of the fire were people smoking. Because there were rags on the floor, when the fag was dropped/ attempted to be put out, it was not fully out and was the ignition source of the fire. Another cause may have been faulty wires/cables from the sewing machines. They may have been rubbing together causing friction, eventually making it hot enough to ignite and start the fire. Another reason may have been that the faulty cables/wires may have caused sparks which again could of caused the fire to start. Lastly, the only other thing I could find/ think of is, back in those days there may of been candles as lights and if one was to be knocked onto the floor where the rags were this again could have caused the fire to break out.
The most likely explanation to the spread of the fire is that the hanging patterns, the rags on the floor and the shirts that were already made would be everywhere around the factory meaning it would spread very quickly. Lastly, in those day the factory may of only been small and if the fire started in a corner it would spread even quicker than it would of done if it was in the middle of the room.
There are ways in which the fire could have been prevented. For example if the already make shirts were stored in a separate room, if the rags were pick up and put into a bin every time a bit was dropped or cut etc. Another way it could be prevented if people were not allowed to smoke in the work place and if the sewing machines were to be checked every so often and fixed if there were faults cables/wires.