Separation Science and Functional Groups

Question 1

What is the cause of molecules’ reactions and interactions as well as their characteristic properties?

Answer 1

Functional Groups

Question 2

What two things impart a drug’s properties (for the most part)?

Answer 2

Shape

Functional group

Question 3

What type of hydrocarbons are said to be saturated?

Answer 3

Alkanes

Question 4

How can carbon form double-bonds?

Answer 4

Using side-on overlap between p-orbitals

Question 5

What are the three steps in naming an alkene?

Answer 5

Use the ‘ene’ ending

Count the number of carbon atoms

Say where the double bond is (the lowest number has priority)

Question 6

How do we name a molecule which has two or more of the same feature?

Answer 6

Using a descriptor.

Question 7

What is the descriptor to use when you have two of each feature?

Answer 7

“Di-“

Question 8

What is the descriptor to use when you have three of each feature?

Answer 8

“Tri-“

Question 9

What is the descriptor to use when you have four of each feature?

Answer 9

“Tetra-“

Question 10

What is the descriptor to use when you have five of each feature?

Answer 10

“Penta-“

Question 11

What is the descriptor to use when you have six of each feature?

Answer 11

“Hexa-“

Question 12

What is the descriptor to use when you have seven of each feature?

Answer 12

“Hepta-“

Question 13

What is the descriptor to use when you have eight of each feature?

Answer 13

“Octa-“

Question 14

What is the descriptor to use when you have nine of each feature?

Answer 14

“Ennea-“

Question 15

What is the descriptor to use when you have ten of each feature?

Answer 15

“Deca-“

Question 16

Where do the numerical descriptors go in the naming of a compound when describing the position of the multiple bond?

Answer 16

Before the “ene” or “yne”

Question 17

What hybridisation do tetrahedral carbons have?

Answer 17

All tetrahedral carbons have sp³ hybrid orbitals

Question 18

What hybridisation do all trigonal planar carbons have?

Answer 18

All trigonal carbons have sp² hybrid orbitals

Question 19

What hybridisation do all linear carbons have?

Answer 19

All linear carbons have sp hybrid orbitals.

Question 20

What hybridisation does a carbon atom that has four single bonds form, and what shape does it take?

Answer 20

A tetrahedral shape

Question 21

What hybridisation does a carbon atom that has two single bonds and one double bond form, and what shape does it take?

Answer 21

A trigonal planar shape.

Question 22

What hybridisation does a carbon atom that has two double bonds form, and what shape does it take?

Answer 22

A linear shape.

Question 23

How do you prepare a TLC plate?

Answer 23

Draw a pencil line about 1 cm from the bottom of the plate Spot a TLC plate with the compounds or mixtures we wish to identify We place this in a developing jar which already contains our mobile phase (solvent) to a depth less than 1 cm.

Question 24

What happens in a TLC?

Answer 24

The mobile phase travels up the plate (capillary action) As it does this, the spots of compound also move, depending on the strength of their interaction with the stationary phase (mainly their polarity)

Question 25

How will the polarity effect which spot will move the most in TLC?

Answer 25

The least polar spot will move the most The most polar spot will move the least

Question 26

Why does a non-polar compound move further up the plate in TLC?

Answer 26

A non-polar compound will dissolve more in the mobile phase, thereby spending more time in that phase and hence move further up the plate

Question 27

Why does a polar compound not move as far up the plate in TLC?

Answer 27

A polar compound will interact less with the mobile phase and will also be attracted more to the silica of the stationary phase, hence it won’t move as much.

Question 28

What is the ratio of the distance travelled by the spot versus the mobile phase called?

Answer 28

The Rf (Retention Factor)

Question 29

What is the formula for Rf?

Answer 29

The distance moved up the plate/The distance the solvent moved up the plate.

Question 30

Are there any hydrocarbon-based functional groups?

Answer 30

Yes. They are less polar.

Question 31

Why is Carbon Dioxide heavier than water if it is a gas?

Answer 31

It is linear and hence non-polar

Question 32

What will unsaturated molecules react with in particular?

Answer 32

Hydrogen atoms

Question 33

What is the simplest alkene?

Answer 33

Ethene. You can’t have methene as there is only one carbon and hence it can’t double bond to another carbon.

Question 34

Which is better?: 1 Hexene or Hex-1-ene and why?

Answer 34

Hex-1-ene is better because it’s clear what the 1 is referring to.

Question 35

Do you need to number the position of the double bond in propene?

Answer 35

No, because it’ll always be 1.

Question 36

Which is correct: Hexdiene or Hexadiene?

Answer 36

Hexadiene. This is a convention because it would be difficult to pronounce the ‘x’ and ‘d’ together.

Question 37

What alignment do triple bonds have?

Answer 37

Linear, so you can’t draw the skeletal structures with angles between a double bond.

Question 38

Are double bonds linear?

Answer 38

No, so you must draw an angle when representing a double bond in a skeletal structure.

Question 39

If you have a sp3 hybridised carbon, what molecule will it tend to bind to?

Answer 39

If you have a sp3 hybridised carbon, the molecule it bonds to tends to be sp3 unless it has further unsaturation