exp 3 post lab Flashcards
SIMPLE VS STEAM DISTILLATION
characteristics of sample used
SIMPLE
- Homogenous
- nonvolatile solute + volatile solvent
- OR 2 miscible liquids with one more volatile than the other
STEAM
- Heterogenous
- water + another substance insoluble in water, higher boiling point than water, and slightly volatile
SIMPLE VS STEAM DISTILLATION
main principle + law it follows
SIMPLE
- evaporation and separation of sample based on differences in boiling points (20 - 25C difference)
- Raoult’s Law
STEAM
- co-distillation of water and desired component
- Dalton’s Law of Partial Pressure
SIMPLE Distillation employs what law?
- states that the ____ ____ of a compound is ____ when it becomes a ____ of a ____
RAOULT’s LAW
- vapor pressure
- lowered
- part
- solution
In the experiment, simple distillation was done between ___ and ___
- ethanol and water
what happens if the boiling difference between 2 substances in SIMPLE DISTILLATION is small?
pwede sabay mag boil yung substances sa mixture so di ma s-separate
STEAM Distillation employs what law?
- wherein ___ component of the mixture exerts a _____ ____ that is _____ of the ___ ___ of the ____ components
- the combination of the ____ ___ of both components is _____ than each of their ____ ____ ___
+ Formula
DALTON’s LAW OF PARTIAL PRESSURE
- each
- vapor pressure
- independent
- vapor pressure
- other
- boiling points
- lower
- individual boiling points
P total = P water + P other component
SIMPLE VS STEAM DISTILLATION
temperature at which the mixture boils
SIMPLE
- starts upon reaching the BP of the desired substance or the component that is more volatile/with the lower BP
STEAM
- starts at a temp lower than the BP of both components in the mixture
SIMPLE VS STEAM DISTILLATION
contents of distillate
SIMPLE
- distillate should ONLY contain the desired/lower BP substance
STEAM
- contains both the water and the desired substance (other) as oily droplets
in STEAM distillation, what is the appearance of the separatory funnel that collects the distillate?
*which of the 2 components is more abundant?
2 layers: water and the other component
*mas madaming water compared sa other component
*small portions of the other component dissolves in the water
SIMPLE VS STEAM DISTILLATION
application (suitable for what substances?)
simple (1)
steam (5)
SIMPLE
- separating substances with WIDE DIFFERENCE in boiling points (minimum interval lang yung 20-25)
STEAM
- mixture is liquid
- separate substances that are volatile and water-immiscible
- sensitive to heat
- decompose at high temperature
- mixtures containing large amounts of nonvolatile material (plant sample + water)
SIMPLE VS STEAM DISTILLATION
limitations (2 per each)
SIMPLE
1. cannot be used on those w close boiling pts
2. cannot be used on those that decompose at their BP
STEAM
1. cannot be used on those that react with water or decompose with water contact
2. nonvolatile compounds
SIMPLE VS STEAM DISTILLATION
set-up
simple
SIMPLE
- use of thermometer
- receiver: beaker/erlenmeyer flask
STEAM
- does not require thermometer
- receiver: separatory funnel/erlenmeyer flask
How to keep condenser cold?
water pump to ice bath
why does ESSENTIAL OILS use steam distillation?
steam can penetrate cells of plant sample and release the oils from their packets
why should the plant samples be cut into smaller pieces before distillation?
increases the surface area of contact with the water, making the process more efficient
SALTING OUT PROCESS
- when used?
- allows _____ removal of ____ ___ from ____ through ____ the solubility of the oil from the water
- steam distillation: after the separatory funnel filled up with mixture of water and essential oils (2 layers: aq and organic)
- maximum removal of essential oil from water through reducing the solubility
IMFA between water and essential oil
IMFA between water and salt
LDF
ion-dipole (stronger)
- so water would like to interact more with salt kaya si water lalayo kay water
DALTON’s LAW OF PARTIAL PRESSURE
- dictates how water ____-___ with the _____ compound
- states that the ____ VP of the ____ must equal the _____ _____ at ____Celsius
- co-distills
- desired
- total
- mixture
- atmosphere pressure
- 25
PRESSURE is = to ____ atm, ____ mmHg, and ____ torr
1 atm
760 mmHg
760 torr
Dalton’s Law of Partial Pressures
formulas (2)
P total = P water + P other component
(n oil) / (n steam) = (P oil) / (P steam)
n oil = no. of moles of oil vaporized from mixture
n steam = no. of moles of steam produced during distillation
Molar Mass of Water
18.016 g/mol
number of moles formula
n = (mass of substance) / (molar mass of substance)
the vapor pressure of each compound _____ as temperature ____ or ____
thus, ____ at which distillation occurs should be _____
- vary
- increases
- decreases
- temperature
- specified
in mole ratio “n oil: n steam”, what does a low and high mole ratio indicate?
LOW MOLE RATIO: unting oil lang nakuha, mas madaming tubig
HIGH MOLE RATIO: maraming oil nakuha, unting tubig lang
In problem solving, what if volume ang bigay instead of moles, vapor pressure, or mass?
use density formula
PAALALA sa problem solving?
always check yung VP ng water and oil if equal to 760 mmHg/torr
ALSO check yung units if same ba or if ano hihingi or if naka atm or mmHg
Is P atm always 1 atm?
Yes, automatically IF 25 C
pero kapag di given, you can double check by getting the P total or P water + P oil
