Sc (Z = 21) is a transition element but Zinc (z = 30) is not because _______.

(a)

both Sc³⁺ and Zn²⁺ ions are colourless and form white compounds

(b)

In case of Sc, 3d orbital are partially filled but in Zn these are completely filled

(c)

last electron as assumed to be added to 4s level in case of zinc

(d)

both Sc and Zn do not exhibit variable oxidation states

The catalytic behaviour of transition metals and their compounds is ascribed mainly due to _______.

(a)

their magnetic behaviour

(b)

their unfilled d orbitals

(c)

their ability to adopt variable oxidation states

(d)

their chemical reactivity

The alloy of copper that contain Zinc is________.

(a)

Monel metal

(b)

Bronze

(c)

bell metal

(d)

brass

Permanganate ion changes to ________ in acidic medium.

(a)

MnO₄²⁻

(b)

Mn²⁺

(c)

Mn³⁺

(d)

MnO₂

MnO₄^- react with Br^- in alkaline P^H to give ________.

(a)

BrO₃^- MnO₂

(b)

Br₂, MnO₄^2-

(c)

Br₂, MnO₂

(d)

BrO^-, MnO₄^2-

The number of moles of acidified KMnO₄ required to oxidize 1 mole of ferrous oxalate(FeC₂O₄) is _______.

(a)

5

(b)

3

(c)

0.6

(d)

1.5

Which of the following lanthanoid ions is diamagnetic?

(a)

Eu²⁺

(b)

Yb²⁺

(c)

Ce²⁺

(d)

Sm²⁺

Which of the following oxidation states is most common among the lanthanoids?

(a)

+4

(b)

+2

(c)

+5

(d)

+3

Identify the paramagnetic species.

(a)

Cu⁺

(b)

Cr⁺

(c)

MnO₄

(d)

Zn²⁺

Which of the following is coloured due to charge transfer?

(a)

MnO₄^-

(b)

CrO₄^2-

(c)

Cu₂O

(d)

All of these

CeO₂ & ThO₂

(1)

Long mission space probes

Pu-238

(2)

Rare earth elements

Zr and Hf

(3)

Similar size

f - block elements

(4)

Gas lamp materials

Titanium

(5)

Artificial joint

What are transition metals? Give four examples.

What are inner transition elements?

What are actinides? Give three examples.

Describe the preparation of potassium dichromate.

What are coinage metals?

What are interstitial compounds?

Write the electronic configuration of Ce⁴⁺ and Co²⁺.

Compare lanthanoids and actinoids.

Actinoid contraction is greater from element to element than the lanthanoid contraction, why?

Write chemical equations for the reactions involved in the manufacture of potassium permanganate from pyrolusite ore.

Which is stronger reducing agent Cr²⁺ or Fe²⁺?

Why first ionization enthalpy of chromium is lower than that of zinc?