Chemistry : The p-Block Elements

An organic compound which produces a bluish green coloured flame on heating in presence of copper is :

• chlorobenzene

• benzaldehyde

• aniline

• benzoic acid

Acidified sodium fusion extract on addition of ferric chloride solution gives blood red colouration which confirms the presence of

• S and Cl

• N and S

• N

• S

The number of gram molecules of chlorine in 6.02 × 10²⁵ hydrogen chloride molecules is

• 10

• 100

• 50

• 5

When conc. H₂SO₄ is heated with P₂O₅, the acid is converted into

• sulphur trioxide

• sulphur dioxide

• sulphur

• a mixture of sulphur dioxie and sulphur trioxide

The noble gas mixture is cooled in a coconut bulb at 173 K. The gases that are not adsorbed are

• Ne and Xe

• He and Xe

• Ar and Kr

• He and Ne

Excess of PCl₅ reacts with conc. H₂SO₄ giving 

• chlorosulphonic acid

• thionyl chloride

• sulphuryl chloride

• sulphurous acid

Which is the most easily liquifiable rare gas?

• Xe

• Kr

• Ar

• Ne

Helium is used in balloons in place of hydrogen because it is

• incombustible

• lighter than hydrogen

• radioactive

• more abundant than hyrogen

In the brown ring test, the brown colour of the ring is due to

• ferrous nitrate

• ferric nitrate

• a mixture of NO and NO₂

• nitrosoferrous sulphate

The one which has least iodine value is

• sunflower oil

• ginger oil

• ghee

• groundnut oil