Exercise 1 Question 1
Silver atom has completely filled d orbitals (4d10) in its ground state. How can you say that it is a transition element?

Exercise 1 Question 2
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomization of zinc is the lowest, i.e., 126 kJ mol−1. Why?

Exercise 1 Question 3
Which of the 3d series of the transition metals exhibits the largest number of oxidation states and why?

Exercise 1 Question 4

The E^θ(M²⁺/M) value for copper is positive (+0.34V). What is possibly the reason for this? (Hint: consider its high Δ_aHV and low Δ_hydHV)

Exercise 1 Question 5
How would you account for the irregular variation of ionization enthalpies (first and second) in the first series of the transition elements?

Exercise 1 Question 6
Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?

Exercise 1 Question 7
Which is a stronger reducing agent Cr²⁺ or Fe²⁺ and why?

Exercise 1 Question 9
Explain why Cu⁺ ion is not stable in aqueous solutions?

Exercise 1 Question 10
Actinoid contraction is greater from element to element than lanthanoid contraction. Why?

Ex 2 Question 1
Q1 : Write down the electronic configuration of:
(i) Cr³⁺    (iii) Cu⁺    (v) Co²⁺    (vii) Mn²⁺ 
(ii) Pm³⁺  (iv) Ce⁴⁺  (vi) Lu²⁺   (viii) Th⁴⁺

Question 2
Why are Mn²⁺compounds more stable than Fe²⁺ towards oxidation to their +3 state?

Ex 2 Question 3
Explain briefly how +2 state becomes more and more stable in the first half of the first row transition elements with increasing atomic number?

Ex Question 4
To what extent do the electronic configurations decide the stability of oxidation states in the first series of the transition elements? Illustrate your answer with examples.

Ex 2 Question 5
What may be the stable oxidation state of the transition element with the following d electron configurations in the ground state of their atoms :
3d³, 3d⁵, 3d⁸ and 3d⁴?

Ex 2 Question 7
What is lanthanoid contraction? What are the consequences of lanthanoid contraction?

Ex 2 Question 8
What are the characteristics of the transition elements and why are they called transition elements? Which of the d-block elements may not be regarded as the transition elements?

Ex 2 Question 9
In what way is the electronic configuration of the transition elements different from that of the non-transition elements?

Ex 2 Question 10
What are the different oxidation states exhibited by the lanthanoids?

Ex 2 Question 11
Explain giving reasons:
(i) Transition metals and many of their compounds show paramagnetic behaviour.
 
(ii) The enthalpies of atomisation of the transition metals are high.
 
(iii) The transition metals generally form coloured compounds.
 
(iv) Transition metals and their many compounds act as good catalyst.

Ex 2 Question 12
What are interstitial compounds? Why are such compounds well known for transition metals?

Ex 2 Question 13
How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.

Ex 2 Question 14
Describe the preparation of potassium dichromate from iron chromite ore. What is the effect of increasing pH on a solution of potassium dichromate?

Ex 2 Question 15
Describe the oxidising action of potassium dichromate and write the ionicequations for its reaction with:
(i) iodide
(ii) iron
(II) solution and
(iii) H₂S

Question 16
Describe the preparation of potassium permanganate. How does the acidifiedpermanganate solution react with
(i) iron
(II) ions 
(ii) SO₂ and
(iii) oxalic acid?
Write the ionic equations for the reactions.

Ex 2 Question 17
For M²⁺/M and M³⁺/M²⁺ systems, the E^⊖  values for some metals are as follows:
Cr²⁺/Cr -0.9V
Cr³/Cr²⁺ -0.4 V
Mn²⁺/Mn -1.2V
Mn³⁺/Mn²⁺ +1.5 V
Fe²⁺/Fe -0.4V
Fe³⁺/Fe²⁺ +0.8 V
Use this data to comment upon:
(i) The stability of Fe³⁺in acid solution as compared to that of Cr³⁺or Mn³⁺ and
(ii) The ease with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.

Ex 2 Question 18
Predict which of the following will be coloured in aqueous solution?
Ti³⁺, V³⁺, Cu⁺, Sc³⁺, Mn²⁺, Fe³⁺ and Co²⁺.
Give reasons for each.

Ex 2 Question 20
Compare the chemistry of actinoids with that of the lanthanoids with specialreference to:
(i) electronic configuration
(ii) atomic and ionic sizes
(iii) oxidation stateand
(iv) chemical reactivity.

Ex 2 Question 21
How would you account for the following:
(i) Of the d⁴ species, Cr²⁺ is strongly reducing while manganese (III) is strongly oxidising.
(ii) Cobalt (II) is stable in aqueous solution but in the presence of complexing reagents it is easily oxidised.
(iii) The d¹ configuration is very unstable in ions.

Ex 2 Question 22
What is meant by 'disproportionation'? Give two examples of disproportionation reaction in aqueous solution.

Question 23
Which meatal in the first series of transition metals exhibits +1 oxidationstate most frequently and why?

Ex 2Question 24
Calculate the number of unpaired electrons in the following gaseous ions: Mn³⁺, Cr³⁺, V³⁺ and Ti³⁺. Which one of these is the most stable in aqueous solution?

Ex 2 Question 25
Give examples and suggest reasons for the following features of the transition metal chemistry:
(i)The lowest oxide of transition metal is basic, the highest is amphoteric/acidic.
 
(ii)A transition metal exhibits highest oxidation state in oxides and fluorides.
 
(iii) The highest oxidation state is exhibited in oxoanions of a metal.

Ex 2 Question 26
Indicate the steps in the preparation of:
(i) K₂Cr₂O₇ from chromite ore.
(ii) KMnO₄ from pyrolusite ore.

Ex 2 Question 27
What are alloys? Name an important alloy which contains some of thelanthanoid metals. Mention its uses.

Ex 2 Question 28
What are inner transition elements? Decide which of the following atomic numbers are the atomic numbers of the inner transition elements: 29, 59, 74, 95, 102, 104.

Ex 2 Question 30
Which is the last element in the series of the actinoids? Write the electronic configuration of this element. Comment on the possible oxidation state of this element.

Ex 2 Question 33
Compare the chemistry of the actinoids with that of lanthanoids with reference to:
(i) electronic configuration
(ii) oxidation states and
(iii) chemical reactivity.

Ex 2 Question 35
Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following points:
(i) electronic configurations,
(ii) oxidation states,
(iii) ionisation enthalpies, and
(iv) atomic sizes.

Ex 2 Question 36
Write down the number of 3d electrons in each of the following ions:
Ti²⁺, V²⁺, Cr³⁺, Mn²⁺, Fe²⁺, Fe³⁺, CO²⁺, Ni²⁺ and Cu²⁺.
Indicate how would you expect the five 3d orbitals to be occupied for these hydrated ions (octahedral).

Ex 2 Question 38
What can be inferred from the magnetic moment values of the following complex species?
Example Magnetic Moment (BM)
K₄[Mn(CN)₆] 2.2
[Fe(H₂O)₆]²⁺ 5.3
K₂[MnCl₄] 5.9