Excess of PCl₅ reacts with conc. H₂SO₄ giving 

• chlorosulphonic acid

• thionyl chloride

• sulphuryl chloride

• sulphurous acid

452.

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

In which of the following, NH₃ is not used?

• Tolles's reagent

• Nessler's reagent

• Group reagent for the analysis of IV group basic radicals

• Group reagent for the analysis of III group basic radicals

Argon is used

• in filling airships

• to obtain low temperature

• in high temperature welding

• in radiotherapy for treatment of cancer

The incorrect statement in respect of chromyl chloride test is

• formation of red vapours

• formation of lead chromate

• formation of chromyl chloride

• liberation of chlorine

The number of naturally occurring p block elements that are diamagnetic is

• 18

• 6

• 5

• 7

In Kjeldahl's method, ammonia from 5 g of food neutralizes 30 cm³ of 0.1 N acid. The percentage of nitrogen in the food is

• 0.84

• 8.4

• 16.8

• 1.68