Boiling point determination lab PDF

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BOILING POINT LAB

INTRODUCTION A substance's boiling point is a beneficial physical property for characterizing pure compounds. The transition from solid to liquid, like the transition from solid to liquid, necessitates the use of heat. The heat has no effect on the temperature of the substance but is used to boil the substance, which majorly remains at a constant temperature throughout the boiling process. This experiment aims to measure the freezing point, the temperature at which a liquid freezes, and boiling point of water in order to measure and determine the accurate boiling point of an unknown liquid.

CHEMICAL RESPONSIBILITY The unknowns. used in this experiment are one of the following substances: methanol, ethanol or isopropyl alcohol (rubbing alcohol), Methanol-flammable liquid, toxic by ingestion Ethanol-flammable liquid, toxic by ingestion Isopropyl alcohol-{rubbing alcohol) flammable liquid, toxic by ingestion. In order to dispose of the unknown substance it is required to return the vial with the substance to where it was taken from

DISCUSSION Discussion of Results: During the calibration of the thermometer, the freezing and boiling point of the water was obtained. The freezing point of water is O degrees Celsius, however my recorded temperature was -1 degrees Celsius. There is an error of +1 degrees Celsius. The boiling point of water is 100.3 degrees Celsius, however, my recorded temperature was 105 degrees Celsius, therefore, there was a correction of -4.7 degrees Celsius made. This is shown on the graph in the calculations section that shows linear

variation of Correction with Temperature (degrees Celsius), this graph helps determine the correct BP of the unknown substance which was calculated to be 77.4 degrees Celsius. During the experiment to find the boiling point of an unknown substance, the boiling points were done on two tries and they were averaged out to be 81 degrees Celsius and 80 degrees Celsius, as the second trial was close to the first number I used the first result to measure the

correct BP of the unknown substance. The causation for the errors could be minor changes to the calibration. Some factors could be environmental changes, not waiting for the temperature bulb to continue moving and recording too low of a temperature, and some additional particles in the unknown. To make the experiment more accurate, using the capillary method to measure the boiling point of the liquid could help.

CONCLUSION The boiling point determination experiment allowed students to observe the boiling points of water and establish an unknown substance by the boiling point. This physical property is deemed significant to the understanding of organic

compounds. The unknown substance is Ethanol as the boiling point I calculated was closest to the boiling point of Ethanol. I think the experiment was successful as I was able to identify the unknown substance....