Write one difference between α -helix and β -pleated structures of proteins.

Why is bithional added to soap?

What is tincture of iodine? Write its one use.

Among the following, which one acts as a food preservative?
Aspartame, Aspirin, Sodium Benzoate, Paracetamol

55.

Shyam went to a grocery shop to purchase some food items. The shopkeeper packed all the items in polythene bags and gave them to Shyam. But Shyam refused to accept the polythene bags and asked the shopkeeper to pack the items in paper bags. He informed the shopkeeper about the heavy penalty imposed by the government for using polythene bags. The shopkeeper promised that he would use paper bags in future in place of polythene bags.

Answer the following :

(a) Write the values (at least two) shown by Shyam

(b) Write one structural difference between low-density polythene and high-density polythene.

(c) Why did Shyam refuse to accept the items in polythene bags?

(d) What is a biodegradable polymer ? Give an example

Write the reactions involved in the following :

Hofmann bromamide degradation reaction

Write the reactions involved in the following :

Diazotisation

Write the reactions involved in the following :

Gabriel phthalimide synthesis

Give reasons:
(CH₃)₂NH is more basic than (CH₃)₃N in an aqueous solution.

Give reasons:

Aromatic diazonium salts are more stable than aliphatic diazonium salts.