641.

How many structural isomers are possible for C₄H₉Cl ?

• 2

• 4

• 8

• 10

What are constituents of 'Mischmetal'?

• La, Fe

• La, Ce

• Fe, Ce

• Ce, Cu

Fungicides are organic compounds of :

• mercury

• fluorine

• lead

• chlorine

In the periodic table actinides occupy :

• III B group in 7th row

• III B group in 6th row

• III B group in 5th row

• None of the above

Which of the following is diamagnetic ?

• CuCl₂

• NiCl₂

• FeCl₃

• Cu₂Cl₂

Why Sc (Z = 21) is not considered as transition element ?

• Properties of Sc are similar to alkali metals

• 3d - orbitals are empty in its stable compound

• Stable oxidation number of Sc is +2

• Atomic volume of Sc is very large

The properties of Zr and Hf are same because :

• they have similar radii

• they belong to d-block

• they have same valence electrons

• None of the above

Formation of coloured solution is possible when metal ion in the compound contains :

• paired electrons

• lone pair of electrons

• unpaired electrons

• None of the above

In the periodic table metals usually used as catalysts belong to :

• f - block

• d - block

• p - block

• s - block

In a neutron induced reaction of ${}_{92}{}^{235}\mathrm{U}$ , the product obtained is ${}_{37}{}^{95}\mathrm{Rb}$ , three neutrons and an element (new nuclide) .The other new nuclide is :

• ${}_{55}{}^{138}\mathrm{Cs}$

• ${}_{56}{}^{140}\mathrm{Ba}$

• ${}_{54}{}^{144}\mathrm{Xe}$

• ${}_{38}{}^{90}\mathrm{Sr}$