d and f block

Metal ion are paramagnetic in nature because:

• (a) They form coloured salts

• (b) They have one or more unpaired d- electrons

• (c) They have one or more s- paired electron

• (d) They are reducing agents

In the first transition series the highest oxidation state is exhibited by:

• (a) Mn

• (b) Ni

• (c) Fe

• (d) Cr

Zr and Hf have almost equal atomic and ionic radii because:

• (a) Of diagonal relationship

• (b) Of Lanthanide contraction

• (c) Actinide contraction

• (d) Both belong to same transition series

What is the magnetic moment of K3[FeF6]?

• (a) 5.91 B.M

• (b) 4.89 B.M

• (c) 3.87 B.M

• (d) 6.92 B.M

Which of the following has the least magnetic moment?

• (a) Cu2+

• (b) Ni2+

• (c) Co2+

• (d) Fe2+

The number of unpaired electrons in gaseous species of Mn3+, Cr3+ and V3+ respectively are:

• (a) 4, 4 and 2

• (b) 3, 3 and 2

• (c) 4, 3 and 2

• (d) 3, 3 and 3

The highest magnetic moment is shown by the transition metal ion with the electronic configuration:

• (a) 3d2

• (b) 3d7

• (c) 3d9

• (d) 3d5

Zinc and mercury do not show variable valency like d-block elements because

• (a) they are soft

• (b) their d-shells are complete

• (c) they have only two electrons in the outermost subshell.

• (d) their d-shells are incomplete

The melting points and boiling points up to the middle of 3d- series

• (a) Increases

• (b) Decreases

• (c) Remain same

• (d) No regular

Highest Oxidation State manganese in fluoride is +4 (MnF4) Highest Oxidation State in oxide is +7 (Mn2 O7) because:

• (a) fluorine is more electronegative than oxygen

• (b) fluorine does not possess d orbitals

• (c) fluorine stabilizes lower oxidation State

• (d) In covalent compounds, fluorine can form only single bonds while oxygen Form double bond.