Module 6:analysis

Question 1

Chromatography
What is chromatography

Answer 1

Analytical technique used to separate and identify component moleucles of a mixture

Question 2

Chromatography
What are the two phases

Answer 2

Mobile
Stationary

Question 3

Chromatography
What is the mobile phase

Answer 3

Fluid that allows molecules to move over or through the stationary phase such as liquid or gas

Question 4

Chromatography
What’s true for species thaty are more soluble in the mobile phase

Answer 4

Move further or faster within mobile phase

Question 5

Chromatography
What is the stattionary phase

Answer 5

Substance that has afffinity to it oleucles in the mixture being analysed

Question 6

Chromatography
What dies a greater affinity to the stattionary phase mean

Answer 6

Shorter the distance or slower moves within the mobile phase

Question 7

Chromatography
What is rf value

Answer 7

Retention factor that is unique to each different component moleucles in the mixture being analysed

Question 8

Chromatography
How do you calculate rf

Answer 8

Distance moved by molecule / distance moved by solvent
Al;ways less than 1

Question 9

Chromatography
Why does rf change

Answer 9

Different moleucles have different affinities for mobile stattionary phase

Question 10

Chromatography
What are types of chromatography

Answer 10

TLC
Liquid
Gas
Hplc

Question 11

Chromatography
What happens in tlc

Answer 11

Metal plate coated in thin layer of silica sample dotted on plate paced above level of solvent
Solvent moves up plate separating substances
Dried then chemical traces viewed using uv lamp or using developing agent

Question 12

Chromatography
What happens in gas chromatography

Answer 12

Thin coiled tube packed with a solid powdered substance that acts as the stationary phase high pressure gas passed through tube and acts as mobile phase
Machine records a retention time for each component in the mixture