The number of bridged oxygen atoms present in compound B formed from the following reactions is

Pb(NO₃)₂ $$\buildrel {673\,K} \over \longrightarrow $$ A + PbO + O₂

A $$\buildrel {Dimerise} \over \longrightarrow $$ B

The metal ion (in gaseous state) with lowest spin-only magnetic moment value is :

Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Polluted water may have a value of BOD of the order of 17 ppm.

Reason R : BOD is a measure of oxygen required to oxidise both the bio-degradable an non-biodegradable organic material in water.

In the light of the above statements, choose the most appropriate answer from the options given below.

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : A mixture contains benzoic acid and napthalene. The pure benzoic acid can be separated out by the use of benzene.

Reason R : Benzoic acid is soluble in hot water.

In the light of the above statements, choose the most appropriate answer from the options given below.