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Orgchem 1st Lab Exam 🤞 > paper and thin-layer chromatography > Flashcards

paper and thin-layer chromatography Flashcards

1
Q

Stationary phase: Plate (paper or tlc) in PAPER CHROMATOGRAPHY

A

Water (adhering on the paper)
**liquid-polar

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2
Q

Stationary phase: Plate (paper or tlc) in THIN-LAYER CHROMATOGRAPHY

A

Silica (solid - polar)

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3
Q

Mobile Phase (Solvent System) in PAPER CHROMATOGRAPHY

A

ethanol: ammonium hydroxide
** liquid - polar

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4
Q

Mobile Phase (Solvent System) in THIN-LAYER CHROMATOGRAPHY

A

75% pet.ether: 25% acetone
** nonpolar

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5
Q

Means of visualization in PAPER CHROMATOGRAPHY

A

spray w/ Ninhydrin

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6
Q

Means of visualization in THIN-LAYER CHROMATOGRAPHY

A

UV Light

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7
Q

What type of chromatography is a paper chromatography

A

Ascending

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8
Q

What type of chromatography is a THIN-LAYER CHROMATOGRAPHY

A

Ascending

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9
Q

Compound separated in PAPER CHROMATOGRAPHY

A

Amino Acids

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10
Q

Compound separated in THIN-LAYER CHROMATOGRAPHY

A

Analgesics

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11
Q

Advantages in PAPER CHROMATOGRAPHY

A

-Cheap
-best for polar compounds

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12
Q

Advantages in THIN-LAYER CHROMATOGRAPHY

A

-Faster
-Develop more compact spots

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13
Q

what will happen if the applied spots are too large

A

the developed spots will overlap and also results to tailing

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13
Q

The portion of the paper which we happen to touch also develop violet spots. This means that sweat contains ________

A

amino acids

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13
Q

what happens if the solvent level is above the applied spots

A

the spotted compounds will dissolve in the solvent system

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14
Q

what will happen if the solvent is allowed to overrun the paper or TLC plate

A

we cannot compute the Rf value

15
Q

In TLC, the solvent system, the mobile phase is _______. ________, the stationary phase is polar

A

nonpolar

16
Q

The greater the Rf, _________

A

the more nonpolar the analgesic

17
Q

Formula for the Retention factor (Rf)

A

Rf = distance travelled by substance/ distance travelled by solvent

18
Q

what compound will elute first on the plate

A

compount with HIGHEST Rf value

19
Q

The Higher Rf, the ________ the compound, thus ________

A

less polar
basic

20
Q

relationship between Rf values and Polarity

A

inversely proportional

21
Q

why is it necessary to maintain a saturated vapor atmosphere in the developing chamber?

A

to stop the solvent from evaporating as it rises uo the paper. too much solvent evaporated from the plate and components will not move as far

22
Q

what can be done to improve the results in the experiment (paper and thin layer chromatography)

A

proper location and exact estimation of middle point must be done

23
Q

the physical separation of the components of a mixture on the basis of their differing affinities for a stationary phase vs. a mobile phase.

A

Chromatography

24
Q

In ________ chromatography, the mixture is spotted onto a sheet of paper

A

Paper

25
Q

paper chromatography works because of

A

the capillary action of water/solvent in the paper

26
Q

this allows us to separate compounds due to the attraction, or affinity, of the compounds for tge mobile phase vs the stationary phase

A

Capillary action

27
Q

the relative distance of travel of the substance to that of the solvent

A

Retention factor (Rf)

28
Q

It forms colored compounds with amino acids

A

Ninhydrin

29
Q

why does changing the solvent system would result toba different Rf value

A

altering the solvent system can change the relative positions of the separated compounds, resulting in different Rf values.

30
Q

the technique of separation and identification of chemical substance by a MOVING SOLVENT on a thin layer of suitable adsorbent with a binder serving as inert support for the layer

A

Thin-layer chromatography

Orgchem 1st Lab Exam 🤞 (3 decks)

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