The group of elements in which the differentiating electrons enters in the antepenultimate shell of atoms are called :

• f - block elements

• p - block elements

• s - block elements

• d - block elements

Brass, bronze and german silver have one common metal . This is :

• Zn

• Fe

• Al

• Cu

633.

When calomel is treated with ammonium hydroxide, a black substance is formed. The black substance is

• Hg + HgO

• HgO.HgCl₂

• H₂N-Hg-Cl+Hg

• Hg(NH₂)₂ + HgO

Which is not stable under ambient condition?

• ${\mathrm{TiO}}_{2, }{\mathrm{Ti}}^{+4}$

• $\mathrm{VO}, {\mathrm{V}}^{+4}$

• ${\mathrm{VO}}_{2, }{\mathrm{V}}^{+5}$

• ${\mathrm{Cu}}_2\mathrm{O}, {\mathrm{Cu}}^{+2}$

Magnetic moment of Cr²⁺ is nearest to

• Fe²⁺

• Mn²⁺

• Co²⁺

• Ni²⁺

Assertion : Ce⁴⁺ is used as an oxidising agent in volumetric analysis.

Reason : Ce⁴⁺has the tendency of attaining + 3 oxidation state

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : La(OH)₃ is more basic than Lu(OH)₃

Reason : Size of Lu3⁺ increases and shows more covalent character.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false

Lanthanum the first element of lanthanide series has :

• only unfilled 3d orbitals

• unfilled 3d and 4d orbitals

• unfilled 4d and 4forbitals

• unfilled 4f and 5d orbitals

Assertion : F^- ion is a weak ligand and forms outer orbital complex.

Reason : F^- ion cannot force the electrons of d_{${\mathrm{z}}^2$} and d${\mathrm{x}}^2-{\mathrm{y}}^2$ orbitals of the inner shell to occupy d_xy, d_yz and d_zx orbitals of the same shell.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Which of the following has more unpaired d-electrons ?

• Zn

• Fe²⁺

• Ni³⁺

• Cu⁺