Isolating your Compound
Separate Mixtures
Before properties can be determined pure compounds must be isolated. If the starting point is a mixutre then the mixutre must be separated. Before properties can be accuratly determined the compound must be free of inpurites.
Mixtures of liquids are separated by distilation. Mixtures of solids are separated using differing solubilities in Ether, Base, and Acid.
Remove Impurities
Purification is the removal of impurities. Liquids are purified using distilation, while as solids are purified using recrystalization
Compounds must be free of impurities to obtain accurate measurments!Determine Phase Change Temperatures
Liquids
Boiling points (BP) are determined as the maximum temperature before the sample is completly vaporized during distilation
Thermometers have a lag time, so substance may be fully evaporated before the thermometer has a reading
Solids
Melting points (MP) are determined after recrystalized crystals are completly dry (usually 2 days after recrystalization) in the MelTemp device
Determine Index of Refraction
Liquids
Use the refractometer (using manufacturer's guidelines) to determine the index of refraction (RD) on freshly distilled liquid sample.
To read the refractometer you must ajust the focus of the black horizon, afterwards you center it in the crosshairs.
Solids
Solids do not have refractive indexes.
