Aromatics And Amines

Question 1

What is the hydrogenation value for cyclohexa13diene and why (3)

Answer 1

-239 to -121

It is more stable because some overlap of p orbitals so delocalised electrons

Question 2

How do hydrogen bonds from between polypeptide chains

Answer 2

The electron deficient H+ in the nitrogen attracts the lone pair on oxygen of C=O

Question 3

Which structures are secondary
Which one is tertiary

Answer 3

Alpha helix and beta pleated

Disulphide bridge

Question 4

How do amines react with water
And why
What type of reaction is it

Answer 4

Accept a proton
They are bases
Reversible (not strong base)

Question 5

Why is benzene a planar molecule

Answer 5

The c c bonds are all the same length and

All have bond angle between a CC single bond and cc double bond

Question 6

Why is benzen toxic

Answer 6

It is carcinogenic

Question 7

Why so methylbenzene not reactive than Benz e

Answer 7

Methyl group releases electrons into delocalised system which makes it more attractive to electrophiles

Question 8

Equation for nitrobenzene electrophiles

Answer 8

Hno3 and h2so4

No2+
Hso4-
Water