D block elements are elements found in the modern periodic table from the third to the twelfth groups. These elements’ valence electrons are in the d orbital. Transition elements or transition metals are another name for D block elements.
- 3d- Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn
- 4d- Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd
- 5d- La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg
- 6d- incomplete.
Lanthanoids and actinoids are the two series of F block elements. This group of elements is known as the inner transition metals because it provides a transition between the s and d blocks of the periodic table in the sixth and seventh rows.
- Lanthanide series or 4f series (Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm , Yb)
- Actinide series of 5f series ( Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, Mo)
Download Class 12 chemistry Chapter 8 The d & f Block Elements PDF – Set 5
CBSE Class 12 Chemistry Chapter 8 The d & f Block Elements Worksheet – Set 5
Q1. Differentiating electron in inner transition elements enters which orbital?
a.) s
b.) p
c.) d
d.) f
Q2. Which of the following will have smallest ionic radius?
a.) Nd3+
b.) Dy3+
c.) Lu3+
d.) Pm3+
Q3. Which of the following is used as catalyst in the hydrogenation of oil?
a.) V2O5
b.) Pd
c.) Fe
d.) Ni
Q4. d-block elements form complexes because they have:
a.) vacant orbitals
b.) small sizes
c.) high nuclear charge
d.) All of the above
Q5. In dichromate ion how many Cr – O bonds are equivalent?
a.) 4
b.) 6
c.) 8
d.) All bonds are equivalent
Q6. MnO is basic whereas Mn2O7 is acidic in nature.
Q7. Why does manganese exhibits the highest oxidation state of +7 among the 3d-series of transition elements?
Q8. Explain why silver is a transition metal but zinc is not?
Q9. Can lanthanum ion (Z=57) exist in +4 oxidation state? Justify your answer.
Q10. What is the basic difference between the electronic configurations of transition and inner transition elements?
Q11. What are interstitial compounds? Why are such compounds well known for transition metals?
Q12. The actinoids exhibit a larger number of oxidation states than the corresponding members in the lanthanoid series.
Q13. Calculate the ‘spin only’ magnetic moment of M2+ (aq) ion (Z = 27).
Q14. What is the equivalent weight of KMnO4 in-
i.) acidic medium
ii.) alkaline medium if its molecular weight is 158.
Q15. How would you account for the following:
i.) Cr2+ is reducing in nature while with the same d-orbital configuration (d4), Mn3+ is an oxidizing agent.
ii.) In a transition series of metals, the metal which exhibits the greatest number of oxidation states occurs in the middle of the series.
Q16. i.) Transition metals and their compounds are generally found to be good catalysts.
ii.) Metal-metal bonding is more frequent for the 4d and the 5d series of transition metals than that for the 3d series.
Q17.
i.) Complete the following chemical reaction equations:
(a) Fe2+ (aq) + MnO4– (aq) + H+ (aq) →
(b) Cr2O72– (aq) + I– (aq) + H+ (aq) →
ii.) With the same d4 d-orbital configuration Cr2+ ion is reducing while the Mn3+ ion is oxidizing.
iii.) The enthalpies of atomization of the transition elements are quite high.
Q18.
i.) Write the formula of an oxo-anion of Manganese (Mn) in which it shows the oxidation state equal to its group number.
ii.) Both O2 and F2 stabilize high oxidation states of transition metals but the ability of oxygen to do so exceeds that of fluorine.
iii.) Copper atom has completely filled d orbitals (3d10) in its ground state, yet it is regarded as a transition element.
Q19. Explain the following-
(i) Why do transition elements show variable oxidation states?
(ii) Name the element showing maximum number of oxidation states among the first series of transition metals from Sc(Z=21) to Zn(Z=30).
(iii) Name the element which shows only +3 oxidation state.
(iv) What is lanthanoid contraction? Name an important alloy which contains some of the lanthanoid metals.
Q20. Explain the following observations:
(a) La3+ (Z = 57) and Lu2+ (Z = 71) do not show any colour in solutions.
(b) Among the divalent cations in the first series of transition elements, manganese exhibits the maximum paramagnetism.
(c) Cu+ ion is not known in aqueous solutions.
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