Unit 4 Flashcards Preview

Chemical Reactivity > Unit 4 > Flashcards

Flashcards in Unit 4 Deck (17)
Loading flashcards...
1
Q

What does plane polarised mean?

A

Light usually has electric fields pointing in many directions. If it meets a material that makes it point in one direction it is said to be plane polarised

2
Q

What does chiral mean? And what does an carbon need in order to be chiral

A

cannot be superimposed and can rotate plane polarised light. Mirror images. A carbon needs 4 different atoms to bond to it

3
Q

What is a chiral carbon usually called?

A

Stereogenic (hasn’t got symmetry)

4
Q

What is the enantiomorphism?

A

type of isomerism concerned with chiral molecules

5
Q

What is the mirror image pair of stereoisomers called?

A

Enantiomers (two molecules that are mirror images of each other but cant be superimposed)

6
Q

What do a pair enantiomers have in common

A

same melting points boiling point nmr mass spectra…

7
Q

How can you tell a pair of enantiomers apart?

A

By how they interact with plane polarised light rotates clockwise or anticlockwise . measure with polarimeter

8
Q

What is a compound which can rotate the plane of polarised light called?/

A

optically active

9
Q

What is a racemic mixture?

A

50% 50% of each enantiomer, it will have no affect on plane polarised light as the affects cancel each other. It is optically inactive

10
Q

What numbers correspond to ortho meta para?

A

ortho- 1.2
Meta- 1,3
Para- 1,4

11
Q

What conditions and reagents are needed to form bromobenzene from benzene?

A

Bromine and an acid catalyst

12
Q

Benzene with sulfuric acid and nitric acid gives what?

A

Nitrobenzene

13
Q

What is a diastereomer?

A

A molecule with two stereo-centres

14
Q

If benzene is mixed with potassium permanganate will happen?

A

It wont react

15
Q

What does a methyl substituent do on an aromatic ring?

A

Activating, ortho and para directing

16
Q

Treatment of benzyl alcohol with potassium dichromate will give what?

A

A carboxylic acid

17
Q

What effect does a chloro substituent have on an aromatic ring?

A

Its deactivating but ortho and para directing because it can donate electrons