chapter 2

Question 1

what is an RF?

Answer 1

RF=solution divided by solvent

Question 2

column:
1. eluant
2. absorbant
3. advantages
4. disadvantages

Answer 2

1. h2O,alcohol,acids
2. CaCo3,Powderd Cellulose, resin
3. handles and separates large quantities
4. Time consuming, no permanent record

Question 3

paper:

1. eluant
2. absorbant
3. advantages
4. disadvantages

Answer 3

1. H2O, alcohol, organic solvents
2. chromatography paper
3. permanent record, cheap, easy, convenient
4. small quantities

Question 4

Gas/Liquid

1. eluant
2. absorbant
3. advantages
4. disadvantages

Answer 4

1. N2 or He
2. powderd earth,crushed fire brick
3. very fast, can separate very complex mixtures, permanent record
4. very expensive, technology is complicated, small quantities

Question 5

why is to more reliable than distance traveled when determining the identity of unknowns?

Answer 5

the distance travelled by solutions and solvents may differ but the distance between the (which is the rf) is constant

Question 6

why is it advisable to use a different solvent when running a two dimensional paper chromatograph in the second direction?

Answer 6

some solutions may be soluable in certain types of sovents onlyand may be insoluable to other solvents. this means that we have to use different solvents to dissolve certain solutions so the solutions can move outwards on the paper.

Question 7

what are the 3 types of chromotography used?

Answer 7

• Column chromotography
• paper chromotography
• gas/liquid chromotography