Lithium, Sodium and potassium were put in the same group on the basis of their similar properties.
i) What is the similarity in their properties?

An organic compound burns with a sooty flame. Is it a saturated or an unsaturated compound?

(i) Alcohols are converted into carboxylic acid only under ……….

(ii) In partial oxidation; alcohols are converted into …………..

i. What is observed when a solution of potassium iodide is added to a solution of lead nitrate taken in a test tube?

ii. What type of reaction is this?

iii. Write a balanced chemical equation to represent the above reaction.

OR

A brown substance ‘X’ on heating in air forms a substance ‘Y’. When hydrogen gas is passed over heated ‘Y’, it again changes back into ‘X’.

i. Name the substance ‘X’ and ‘Y’

ii. Name the type of chemical reactions occurring during both the changes.

iii. Write the chemical equations of the reactions.

Account for the following:

a. Cations are smaller in size than the corresponding atom.

b. The noble gases were discovered very late.