Vanadium and variable oxidation states

Question 1

what is the usual source of vanadium and why is it hard to extract?

Answer 1

The usual source of vanadium in the +5 oxidation state is ammonium metavanadate, NH4VO3. This isn’t very soluble in water and is usually first dissolved in sodium hydroxide solution.

Question 2

How can ammonium metavanadate be reduced?

Answer 2

The solution can be reduced using zinc and an acid - either hydrochloric acid or sulphuric acid, usually using moderately concentrated acid.

Question 3

what are the different oxidation states of vanadium?

Answer 3

V(V)
V(IV)
V(III)
V(II)

Question 4

What are the species in acidic solution and colour of the solution of V(V)?

Answer 4

[VO2(H2O)4]+

yellow

Question 5

What are the species in acidic solution and colour of the solution of V(IV)?

Answer 5

[VO(H2O)5]2+

blue

Question 6

What are the species in acidic solution and colour of the solution of V(III)?

Answer 6

[V(H2O)6]3+

green

Question 7

What are the species in acidic solution and colour of the solution of V(II)?

Answer 7

[V(H2O)6]2+

purple

Question 8

How can vanadium be reduced what is the first equation?

Answer 8

2vo2+ +Zn +4H+ to 2V0^2- +Zn2+ +2H20

Question 9

What’s is the second equation for the reduction of vanadium?

Answer 9

2VO^2+ + Zn + 4H20 to 2V^3+ + Zn^2+ + H20

Question 10

What is the third equation?

Answer 10

2V^3+ + Zn to 2V^2+ +Zn2+