chemistry

The d- and f- Block Elements eamcet mcq’s

1. Electronic configuration of a transition element X in +3 oxidation state is

[Ar]3d 5. What is its atomic number?

(i) 25

(ii) 26

(iii) 27

(iv) 24

2. The electronic configuration of Cu(II) is 3d9 whereas that of Cu(I) is 3d10. Which

of the following is correct?

(i) Cu(II) is more stable

(ii) Cu(II) is less stable

(iii) Cu(I) and Cu(II) are equally stable

(iv) Stability of Cu(I) and Cu(II) depends on nature of copper salts

3. Generally transition elements form coloured salts due to the presence of

unpaired electrons. Which of the following compounds will be coloured in

solid state?

(i) Ag2SO4

(ii) CuF2

(iii) ZnF2

(iv) Cu2Cl2

4. On addition of small amount of KMnO4 to concentrated H2SO4, a green oily

compound is obtained which is highly explosive in nature. Identify the

compound from the following.

(i) Mn2O7

(ii) MnO2

(iii) MnSO4

(iv) Mn2O3

5. The magnetic nature of elements depends on the presence of unpaired

electrons. Identify the configuration of transition element, which shows highest

magnetic moment.

(i) 3d7

(ii) 3d5

(iii) 3d8

(iv) 3d2

6. Which of the following oxidation state is common for all lanthanoids?

(i) +2

(ii) +3

(iii) +4

(iv) +5

7. When KMnO4 solution is added to oxalic acid solution, the decolourisation is

slow in the beginning but becomes instantaneous after some time because

(i) CO2 is formed as the product.

(ii) Reaction is exothermic.

(iii) MnO4

– catalyses the reaction.

(iv) Mn2+ acts as autocatalyst.

8. There are 14 elements in actinoid series. Which of the following elements does

not belong to this series?

(i) U

(ii) Np

(iii) Tm

(iv) Fm

 9. Interstitial compounds are formed when small atoms are trapped inside the

crystal lattice of metals. Which of the following is not the characteristic property

of interstitial compounds?

(i) They have high melting points in comparison to pure metals.

(ii) They are very hard.

(iii) They retain metallic conductivity.

(iv) They are chemically very reactive.

10. The magnetic moment is associated with its spin angular momentum and

orbital angular momentum. Spin only magnetic moment value of Cr3+ ion is

___________.

(i) 2.87 B.M.

(ii) 3.87 B.M.

(iii) 3.47 B.M.

(iv) 3.57 B.M.

11. KMnO4 acts as an oxidising agent in alkaline medium. When alkaline KMnO4

is treated with KI, iodide ion is oxidised to ____________.

(i) I2

(ii) IO–

(iii) IO3

–

(iv) IO4

–

12. Which of the following statements is not correct?

(i) Copper liberates hydrogen from acids.

(ii) In its higher oxidation states, manganese forms stable compounds with

oxygen and fluorine.

(iii) Mn3+ and Co3+ are oxidising agents in aqueous solution.

(iv) Ti2+ and Cr2+ are reducing agents in aqueous solution.

13. When acidified K2Cr2O7 solution is added to Sn2+ salts then Sn2+ changes to

(i) Sn

(ii) Sn3+

(iii) Sn4+

(iv) Sn+

14. Highest oxidation state of manganese in fluoride is +4 (MnF4) but highest

oxidation state in oxides is +7 (Mn2O7) because ____________.

(i) fluorine is more electronegative than oxygen.

(ii) fluorine does not possess d-orbitals.

(iii) fluorine stabilises lower oxidation state.

(iv) in covalent compounds fluorine can form single bond only while oxygen

15. Although Zirconium belongs to 4d transition series and Hafnium to 5d

transition series even then they show similar physical and chemical properties

because___________.

(i) both belong to d-block.

(ii) both have same number of electrons.

(iii) both have similar atomic radius.

(iv) both belong to the same group of the periodic table.

16. Why is HCl not used to make the medium acidic in oxidation reactions of

KMnO4 in acidic medium?

(i) Both HCl and KMnO4 act as oxidising agents.

(ii) KMnO4 oxidises HCl into Cl2 which is also an oxidising agent.

(iii) KMnO4 is a weaker oxidising agent than HCl.

(iv) KMnO4 acts as a reducing agent in the presence of HCl