P Block Elements

Answer (d)

With concentrated nitric acid, Al becomes passive due to the formation of a thin protective layer of its oxide on the surface of metal which prevents further reaction.

Answer (d) Hydrogen chloride

\underset{\text{(conc.)}}{ {2H_2SO_{4(aq)}}}

Answer (c) fuming sulphuric acid

is obtained by thermal decomposition of (ammonium nitrite).

\underset{\text{(Oleum)}}{ {H_2S2O7}}

Moist is dried over quick lime . lt cannot be dried over cone. or because being basic it forms Salts with them. Anhydrous also cannot be used because it forms a complex with ammonia.

All the noble gases except radon occur in the atmosphere.

So,



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Answer (d)

is a mixture of and only reacts with to form .

Dilute and concentrated has no effect on Al, Aluminium is rendered passive by nitric acid due to the fopnation of a thin. film of oxide on its surface.
Aluminium dissolves in dil . HCl and liberates dihydrogen.

Aluminium also reacts with aqueous alkali and liberates dihydrogen.