The d- and f- Block Elements Test

Directions For Questions

Transition metal and their compounds are used as catalysts in industry and in biological system. For example, in the Contact Process, vanadium compounds in the $$+5$$ state ($${ V }_{ 2 }{ O }_{ 5 }$$ or $${ VO }_{ 3 }^{ - }$$) are used to oxidise $${ SO }_{ 2 }$$ to $${ SO }_{ 3 }$$:

$${ { SO }_{ 2 } }+\cfrac { 1 }{ 2 } { O }_{ 2 }\xrightarrow [ ]{ { V }_{ 2 }{ O }_{ 5 } } { SO }_{ 3 }$$

It is thought that the actual oxidation process takes place in two stages. In the first step, $${ V }^{ 5+ }$$ is reduced to $${ V }^{ 4+ }$$.

$$2{ V }^{ 5+ }+{ O }^{ 2- }+{ { SO }_{ 2 } }\longrightarrow 2{ V }^{ 4+ }+{ SO }_{ 3 }\quad $$

In the second step, $${ V }^{ 5+ }$$ is regenerated from $${ V }^{ 4+ }$$ by oxygen:

$$2{ V }^{ 4+ }+\cfrac { 1 }{ 2 } { O }_{ 2 }\longrightarrow 2{ V }^{ 5+ }+{ O }^{ 2- }$$

The overall process is, of course, the sum of these two steps:

$${ { SO }_{ 2 } }+\cfrac { 1 }{ 2 } { O }_{ 2 }\longrightarrow { SO }_{ 3 }$$

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The d- and f- B...

Question 1

chromic oxide and nitrogen

chromic acid and ammonia

chromic acid and nitrogen

chromic oxide and ammonia

Question 2

$$Fe$$

$$Ni$$

$$Pt$$

$$Au$$

Question 3

1

2

4

can not be predicted.

Question 4

I, III and III

II, III and IV

I, II and IV

I, III and IV

Question 5

1.06 A

1.56 A

0.85 A

1.35 A

Question 6

decrease in density

decrease in mass

decrease in ionic radii

decrease in radioactivity

Question 7

$${ V }^{ 5+ }$$

$${ V }^{ 4+ }$$

$${ O }^{ 2- }$$

$${ VO }_{ 3 }^{ - }$$

Question 8

$${ Zn }^{ 2+ }$$ has a $${d}^{10}$$ configuration and the $$d$$-subshell is full

$${ Zn }^{ 2+ }$$ shows $$d-d$$ transition

$${ Zn }^{ 2+ }$$ has no electron in the $$4s-$$subshell

$$Zn$$ is not a transition element

Question 9

Small size.

High nuclear charge.

Presence of low energy vacant orbitals to accept lone pair of electrons donated by ligands.

All of the above

Question 10

two O atoms

three O atoms

four O atoms

five O atoms

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