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Organic Chemistry Lab > Module 6: SIMPLE DISTILLATION AND CHROMATOGRAPHY > Flashcards

Module 6: SIMPLE DISTILLATION AND CHROMATOGRAPHY Flashcards

1
Q
  • involves the process of “separating two or more liquids” homogenously mixed but with different boiling points (at least 20 degrees difference)
A

SIMPLE DISTILLATION

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2
Q
  • when the mixture of liquids to be distilled is heated, the “liquid with the _________ boiling point” turns into vapors first
A

lowest

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3
Q
  • as the distillation progresses, the concentration of the lowest boiling component will ___________
A

steadily decrease

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4
Q
  • when the temperature again stabilizes, another pure fraction of the distillate can be collected
A

fractional distillation

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4
Q
  • further acidification of the previous reaction of acetone with sodium nitroprusside and sodium hydroxide using acetic acid will convert the wine-red color into _______________, thereby confirming the distillate as acetone (as elaborated by Le Nobel)
A

magenta-red solution

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5
Q
  • as the solution starts to boil, the liquid with the ______ boiling point turns to vapors first
A

lowest

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5
Q
  • this vapor would then be “condensed back into
    liquid” inside the condenser, which will then be
    collected as the ________
A

distillate

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6
Q

lowering the pressure, thus, lowering the boiling point of the
substance

A

note!

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6
Q

separation of the liquid mixture can be detected through _______

A

ignition test

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6
Q
  • an organic sample (acetone) will ignite, thereby can identifying what type of compound is the ____________
A

distillate

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7
Q

acetone (a ketone) will react with sodium nitroprusside and sodium hydroxide producing a ________________ due to the formation of acetone nitroprusside ion complex

A

wine-red solution

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7
Q

react with acetone (a ketone) producing a wine-red solution

CH3COCH3 + Na2[Fe(CN)5NO] [Fe(CN)5NO(CH2COCH3)] NaOH2+

A

SODIUM NITROPRUSSIDE TEST

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8
Q

reaction of acetone with sodium nitroprusside and sodium hydroxide using _____________ will convert the wine-red color into magenta-red solution

A

GLACIAL ACETIC ACID

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9
Q
  • the process of separating the substances in a complex mixture by their “different affinities” to an “adsorbent”
A

CHROMATOGRAPHY

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9
Q
  • derived from the Greek words, chroma meaning _____, and graphein meaning to _______
A

chroma = color
graphein = write

(literally means color writing)

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9
Q

Chromatography commonly used for analyzing mixtures of
______________

A

colored chemicals

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9
Q
  • this technique involves separation of constituent elements of the mixture
A

Chromatography

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10
Q

Chromatography invented by a Russian botanist, _________________, in 1901, while researching on plant pigments

A

Mikhail Semyonovich Tsvet

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11
Q
  • a liquid or solid that is fixed in a place during the process
A

STATIONARY PHASE

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12
Q
  • usually a high quality filter paper, or an adsorbent
A

STATIONARY PHASE

13
Q
  • either liquid or gas which moves the samples through the stationary phase during the process
A

MOBILE PHASE

14
Q
  • solvent or a mixture of solvents
A

MOBILE PHASE

15
Q

components of the sample will separate readily according to how strongly they “__________ on the stationary phase” versus how readily they “________ in the mobile phase”

A
  1. adsorb
  2. dissolve
15
Q
  • organic compounds interact with adsorbents at different
    ___________________
A

rates and interaction

16
Q
  • it can only have weak Van der Waals forces of attraction for the adsorbent
A

non-polar

17
Q

interacts through “dipole-dipole interactions or hydrogen bonding”

A

polar

17
Q

_________________ absorb strongly on stationary phase (adsorbent)

A

polar compounds

18
Q

__________ will be only weakly absorbed, and thus, has higher affinity with the mobile phase (solvent)

A

non-polar compounds

18
Q

the extent of separation is measure by the _______________

A

retention factor or the Rf value

19
Q

Rf value depends on the
_____________ and
_______________ of the components of the sample

A
  1. relative solubility
  2. adsorptive properties
20
Q

𝑅𝑓 𝑣𝑎𝑙𝑢𝑒 formula

A

𝑅𝑓 𝑣𝑎𝑙𝑢𝑒 =

𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑡𝑟𝑎𝑣𝑒𝑙𝑙𝑒𝑑 𝑏𝑦 𝑡ℎ𝑒 𝑠𝑜𝑙𝑣𝑒𝑛t

21
Q

_____________ draws a developing solvent up the TLC plate

A

capillary action

21
Q

involves a stationary phase made up of an adsorbent (silica gel) coated over an “inert solid plate” (usually aluminum), and a mobile phase made up of a “solvent system” (mixture of appropriate solvents)

A

THIN LAYER CHROMATOGRAPHY

22
Q

the adsorbent will also ______________ part or all the mixture (as more solvent comes by, the mixture will again go into solution, move further and be reabsorbed)

A

reabsorb

22
Q
  • as this solvent pass through the spot, the “mixture will be ________” and will begin to “move with the solvent front”
A

dissolved

23
Q
  • largely depends on adhesion and cohesion forces which allows the mobile phase to move along the stationary phase due to surface tension
A

PAPER CHROMATOGRAPHY

23
Q

passage of the solvent front through the adsorbent is known as _____________

A

developing the plate

23
Q

Paper Chromatography largely depends on __________ and __________

A

adhesion and cohesion forces

24
Q

SIMPLE DISTILLATION
= DISTILLATE B
temperature:?
compound:?
polarity:?
ignition test:?
rxn with Na nitroprusside:?
rxn with acetic acid:?

A

temperature: collected at ~100°C
compound: water
polarity: polar
ignition test: no ignition
rxn with Na nitroprusside: light pink color
rxn with acetic acid: yellow color

24
Q
  • the paper is placed inside a ____________
A

closed chamber/container

25
Q
  • it is important that the solvent level is __________ with samples
A

below the spots

25
Q

container should be covered during the process

A

prevent volatilization

25
Q

PAPER CHROMATOGRAPHY

AMINO ACID: glycine
THEORETICAL Rf VALUE:?

A

0.57

25
Q

spraying the paper with a solution that reacts with the sample allows ___________

A

visualization of the spots

25
Q

the paper is _______________ and then just stands in the bottom of the container

A

coiled or formed into cylinder

25
Q

_________ solution reacts with amino acids giving colored compounds usually brown or purple known as _____________

A
  1. ninhydrin
  2. Ruhemann’s purple
26
Q

SIMPLE DISTILLATION
= DISTILLATE A
temperature:?
compound:?
polarity:?
ignition test:?
rxn with Na nitroprusside:?
rxn with acetic acid:?

A

temperature: collected at ~57°C
compound: acetone
polarity: non-polar
ignition test: burn with luminous flame
rxn with Na nitroprusside: wine red color
rxn with acetic acid: magenta red color

26
Q

PAPER CHROMATOGRAPHY

AMINO ACID: lysine
THEORETICAL Rf VALUE:?

A

0.53

27
Q

PAPER CHROMATOGRAPHY

AMINO ACID: phenylalanine
THEORETICAL Rf VALUE:?

A

0.91

Organic Chemistry Lab (6 decks)

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