Which one of the following ions has the same number of unpaired electrons as present in V³⁺?

(a)

Ti³⁺

(b)

Fe³⁺

(c)

Ni²⁺

(d)

Cr³⁺

The magnetic moment of Mn²⁺ ion is _______.

(a)

5.92BM

(b)

2.80BM

(c)

8.95BM

(d)

3.90BM

Which of the following compounds is colourless?

(a)

Fe³⁺

(b)

Ti⁴⁺

(c)

Co²⁺

(d)

Ni²⁺

Which of the following is wrong with respect to lanthanide contraction?

(a)

Decrease in ionic radii

(b)

Increase in tendency to act as reducing agents

(c)

Decrease in basic character

(d)

Resembles second and third row of d-block elements

Hybridisation of chromium ions and dichromate ions is ________.

(a)

Sp²

(b)

Sp³d

(c)

both (a) and (b)

(d)

None of these

Radioactive

(1)

Similar size

Oxocations

(2)

Promethium

Zr and Hf

(3)

Lanthanido-therrnic process

Lanthanide

(4)

Monazite sand

Metallotherrnic

(5)

Actinides

Why Gd³⁺ is colourles?

Explain why compounds of Cu²⁺ are coloured but those of Zn²+ are colourless.

Which is the most common oxidation state of lanthanoides?

Write the outer electronic configuration of Cr atom (Z=24).

Why is Ce⁴⁺ in aqueous solution is a good oxidising agent?

Explain the variation in E⁰_{M³⁺/M²⁺}  3d series.

(i) Name the transition metal
(a) Which is used in the manufacture of sulphuric add.
(b) That is used in Haber's process.
(c) That have light sensitive properties and act as valuable source in photo graphic industry.
(ii) Write the equations which are involved in the oxidation of hydrogen sulphide to sulphur by KMnO₄ solution.

Transition metals show high melting points. Why?

Write a note on the ionization enthalpy of transition elements.

Write a short note on the oxidation states of 3d series elements.

Compare lanthanoids and actinoids.

What is meant by lanthanoid contraction?

Give reasons for the following
(i) Mn³⁺ is a good oxidising agent.