41.

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

An element with atomic number 21 is a

• halogen

• representative element

• transition element

• alkali metal

Mercury is a liquid metal because

• it has a completely filled s orbital

• it has a small atomic size

• it has a completely filled d orbital that prevents d-d overlapping of orbitals

• it has a completely filled d orbital that causes d-d overlapping

A compound is formed by elements A and B. This crystallises in the cubic structure where the A atoms are at the corers of the cube and B atoms are at the body centres. The simplest formula of the compound is

• AB

• A₆B

• A₈B₄

• AB₆

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

• incombustible

• lighter than hydrogen

• radioactive

• more abundant than hyrogen

The basic principle of Cottnell's precipitatoris

• Le-Chatelier's principle

• peptisation

• neutralisation of charge on colloidal particles

• scattering of light

Hydrogen gas is not liberated when the following metal is added to dil HCl

• Ag

• Zn

• Mg

• Sn

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

Identifythe reaction that does not take place in a blast furnace

• CaCO₃ → CaO + CO₂

• CaO + SiO₂ → CaSiO₃

• 3Fe₂O₃ + 3C → 4Fe+ 3CO₂

• CO₂ + C → 2CO