EXP. 2 & 3 Flashcards
is a separation process for a mixture
of liquids or oils.
DISTILLATION
This is a widely used method for separating liquid
mixtures into their components.
DISTILLATION
A method of separating mixtures based on differences in their
volatilities in a boiling liquid mixture. The components in a
sample mixture are vaporized by the application of heat and
then immediately cooled by the action of cold water in a
condenser.
DISTILLATION
True or False
DISTILLATION method can only be used to separate mixtures where the
components differ narrow in boiling point.
False- narrow-> widely
It utilizes a very simple separation principle: an
intimate contact is created between the starting
mixture and a second phase in order to enhance an
effective mass transfer between the two phases.
Distillation
Refers to the “simple” separation of a solid and a
liquid by evaporating the liquid and collecting it after
it passes through a condenser to be changed into a
liquid state.
SIMPLE DISTILLATION
It uses a simpler apparatus and consumes less
energy and works faster than other types of
distillation
SIMPLE DISTILLATION
Simple Distillation Parts
- Heat Source
- Still Pot
- Still Head
- Thermometer
- Condenser
- Cooling Water In
- Cooling water out
- Distillate/Receiving Flask
- Vacuum/Gas Inlet
- Still Receiver
- Heat Control
- Stirrer speed control
- Stirrer/ Heat Plate
- Heating (Oil/Sand) bath
- Stirrer bar/anti-bumping granules
- Cooling bath
is more complex because of the
need for a longer still process and separate
condensing apparatus but can be operated
continuously.
FRACTIONAL DISTILLATION
Process that separates more than one substance at a
time, is used when boiling points are close together
or mixtures are complex.
FRACTIONAL DISTILLATION
is incapable of significant
purification if the boiling points of the components
are too close.
simple distillation
When the difference in boiling points is less than 100
̊C, a modification is necessary, namely the insertion
of a _____
fractionating column
the insertion
of a fractionating column between the
distilling flask
and three-way adapter
This is used for applications like medicines and
cosmetics where substance purity is very important.
VACUUM DISTILLATION
Used with either simple or fractional types of
distillation but requires careful control because
vacuums tend to lower boiling points.
VACUUM DISTILLATION
VACUUM DISTILLATION
▰ Boiling commences when the vapor pressure of a
liquid or solution equals the
external or applied
pressure (often the atmospheric pressure)
if
the applied pressure is reduced, the boiling point of
the liquid
DECREASES
Vacuum Distillation Parts
- Still Pot
- Short-path distillation head
- Thermometer
- Distillate receiver (Schlenk-type with side-arm)
- Connection to vacuum or inert gas
6.Coolant inlet - Coolant outlet
- Connection to vacuum or inert gas
This is basically the process of separating the
more volatile component, alcohol, from the less
volatile component, water, from a water/alcohol
solution, by heating the solution and condensing
and collecting the alcohol-rich vapors released, as
a high alcohol strength liquid.
ALCOHOLIC DISTILLATION
is the temperature at which the solid and
liquid phases coexist together in equilibrium under a
pressure of one atmosphere.
Melting point
change of a solid into a liquid is _____ and the
reverse is _____
melting; freezing
The amount of heat necessary to,
change one gram of a solid into a liquid at its melting
point is known the
heat of fusion
The melting point of ice
and the freezing point
of water are at ______ temperature.
exactly
the same
Factors Affecting Melting Point
- Molecular force of attraction
- intermolecular force
- intramolecular force
- Molecular size/ molecular weight
- Branching (in organic compounds)
- Polarity
- Type of solid – Amorphous vs. Crystalline
- Atmospheric pressure
Purpose of Melting Point Determination
- Determine the purity of a substance using melting
point as a physical property. - Identify an unknown compound using its melting
point.
Melting point of common drugs:
- Aspirin 134 – 136 degrees C
- Ibuprofen 75 – 77.5 degrees C
- Paracetamol 168 – 172 degrees C
- Potassium chloride 770 degrees C
- Quinapril 120-130 degrees C
