The middle layer of the periodic table is filled with d block elements. The inner d orbits of group 3 to group 13 are filled progressively. On the other hand, f-block elements are found outside at the bottom of the periodic table. In these elements, 5f and 4f orbitals are filled progressively. Three series of transition elements are recognized by the filling of 3d, 4d, 5d orbitals. They have high boiling and melting point. The metallic properties exhibited by the transition elements are-
- Electrical conductivity
- Malleability
- Thermal conductivity
- High tensile strength
- Metallic character
- Ductility
Download Class 12 Chemistry Worksheet Chapter 8 The d & f Block Elements PDF – Set 1
CBSE Class 12 Chemistry Chapter 8 The d & f Block Elements Worksheet – Set 1
Q1. The element of the first transition series which shows the maximum number of oxidation state is-
a.) Mn
b.) Cr
c.) Fe
d.) Cu
Q2. Which is colourless in H2O?
a.) Ti3+
b.) V3+
c.) Cr3+
d.) Sc3+
Q3. Which of the following is not an actinoid?
a.) Cerium
b.) Californium
c.) Uranium
d.) Terbium
Q4. Misch metal is an alloy of-
a.) La
b.) Th
c.) Ac
d.) None of these
Q5. During oxidation in an alkaline medium using KMnO4, the oxidation number of manganese changes from-
a.) +7 to +2
b.) +2 to +7
c.) +7 to +4
d.) +7 to +5
Q6. Ions of Zn2+ and Ti4+ are colourless while Cu2+ and Ni2+ are coloured. Why?
Q7. Why are ionisation energies of 5d elements greater than 3d elements?
Q8. In the transition series, starting from lanthanum (Z= 57), the next element Hf has atomic number 2. Why do we observe this jump in atomic number?
Q9. What are transition elements? Which of the d-block elements are not regarded as transition elements?
Q10. What is lanthanoid contraction? What is the cause of it?
Q11. Name the following:
(i) Divalent ion of first transition series having a maximum magnetic moment.
(ii) Coloured ions of Cu+ and Cu2+.
(iii) Two ions of the first transition series having zero magnetic moment.
Q12. Silver is a transition metal but zinc is not. Why?
Q13. The chemistry of all lanthanoids is so identical. Explain.
Q14. What happens when-
(a) A lanthanoid reacts with dilute acid.
(b) A lanthanoid reacts with water.
Q15. Explain the following observations giving an appropriate reason for each-
(i) The enthalpies of atomisation of transition elements are quite high.
(ii) There occurs much more frequent metal-metal bonding in compounds of heavy transition metals (i.e. 3rd series).
(iii) Mn2+ is much more resistant than Fe2+ towards oxidation.
Q16. Write the chemical equation for the following-
(i) Oxidation of Fe2+ by Cr2O72– in an acidic medium.
(ii) Oxidation of S2O32– by MnO4– in alkaline medium.
(iii) Oxidation of I– by MnO4– in alkaline medium.
(iv) Oxidation of SO32– by Cr2O72– in an acidic medium.
(v) Oxidation of sulphur dioxide by MnO4– in acidic medium.
Q17. The following two reactions of HNO3 with Zn are given:
(a) Zn + conc. HNO3 → Zn(NO3)2 + X + H2O
(b) Zn + dil. HNO3 → Zn(NO3)2 + Y + H2O
Identify X and Y and write balanced equations.
Q18. Account for the following:
(a) Transition metals and the majority of their compound acts as a good catalysts.
(b) From element to element, actinoid contraction is greater than lanthanoid contraction.
Q19. Explain the steps of preparation of potassium dichromate?
Q20. Compare the chemistry of actinoids with that of lanthanoids with special reference to:
(a) electronic configuration
(b) oxidation state
(c) atomic and ionic sizes
(d) chemical reactivity
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