Org Chem Lab Experiment 3

Front 1

what is the general process of distillation

Back 1

vaporize liquid->condense vapor, collect condensed vapor
what is the purpose of distillation

Hint 1

to purify liquid compounds, and to separate molecules

Front 2

which techniques will you be using to separate what compounds

Back 2

use simple and fractional distillation to separate n-pentane from cyclohexane
why is it important to not distill these to dryness

Hint 2

because they are flammable and can lead to explosion

Front 3

what exactly is a boiling point

Back 3

it is when the vapor pressure of liquid phase equals the external pressure.
why do elements have different boiling point

Hint 3

some elements have higher vapor pressure which means it boils at a lower temperature since it takes less heat to increase the vapor pressure to the threshhold.

Front 4

what is the standard boiling point of water

Back 4

100 C at 760 mm Hg
if you are at higher altitude, what will happen

Hint 4

the boiling point will be less since atmospheric pressure is less.

Front 5

in what situations is simple distillation used

Back 5

when the liquid is already almost pure, when there is a non-volatile contaminant (solid), boiling point between two compounds differ by 100C

Front 6

describe what happens (in the graph) where there are two compounds with widely differing b.p.

Back 6

first, the temperature rises to bp of the lower bp compound. when it is distilled it rises immediately to the bp of compound with higher bp.

Front 7

how do you change a simple distillation to fractional distillation, and why is that important

Back 7

insert a fractionating column to increase the surface area
why do we need fractional distillation

Hint 7

to separate moelecules that has a similar boiling point (less than 100C)

Front 8

what determines the efficiency of fractional column

Back 8

the number of vaporization-condensation cycle (theoretical plates) it can go through.

Front 9

what is retention time

Back 9

time it takes for a compound to travel from injection port to detector