Answer:
a. The returning of the process fluid after it has been cooled, condensed or heated in a distillation column or packing.
b. should be stable at high temperatures
should not form other side products
should be reactively inert
c. as a range
d. by taking a series of measurements
e. impure substances melt at lower temperatures.
Explanation:
a. In a reflux, the condensate is returned to the original flask or boiler. This is keep heating the process fluid at a constant temperature without the use of additional fuel. In addition, it increased the molar fraction of the distillate (In other words, it promotes and increased purity in the product)
b. A solvent should be stable, it should not undergo side reactions to form undesirable side products, the solvent should be stable at high temperatures. In addition, the solvent should be chemically inert if possible.
c. It is best to report as a range. Note the experiment is not an ideal set-up, the melting point is determined by many factors.
d. The melting points can be determined by taking a series of measurements graphically.
e. Impure substances lower the melting point.
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