Separation Techniques, Spectroscopy, & Analytical Methods

Thin layer chromatography

separation of components of a mixture based on their polarity.

Stationary phase— polar, adsorbent material like silica (SiO2)

Mobile phase- organic solvent that is less polar than stationary and travels up the stationary phase via capillary action

Separation occurs because the mixture component travel up the plate at different rates depedning on strength of competing intermolecular interactions between mixture component and staionary and mobile phases.

Which of the R?

CH3-substituted benzaldehyde, because it forms fewer hydrogen bonds than the OCH3

Checking the density to know which layer is organic and aqueous layer

GC: L1- ethyl acetate 0.901 g/ml . L2— water/ethanol about 1 g/ml

B&D: L1— water/ethanol L2 chloroform 1.489 g/ml

Sterol should be in the organic layer

and so

BD L2 & GC L1

Answer C

Answer: D

0.5/10 = 1/20

0.5/1 = ½
1/20 × ½ = 1/40

so a dilution of 40

Answer B

Answer B

Types of distillation

Simple

Fractional

Vacuum

Vacuum distillation

performed udner reduced system pressure, wchich lwoers a compound’s boiling point

This is ideal for compounds wiht greater than 150ºC BP

Fractional distillation

Simple distillation

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