Multiple Choice Questions

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Which of the following statement is not correct?

  • La(OH)3 is less basic than Lu(OH)3.

  • In lanthanide series ionic radius of Lu3+ ion decreases.

  • La is actually an element of transition series rather lanthanide.

  • Atomic radius of Zr and Hf are same because of lanthanide contraction.


A.

La(OH)3 is less basic than Lu(OH)3.

As the size of the lanthanide ions decreases from La3+ to Lu3+, the covalent character of the hydroxides increases and hence, the basic strength decreases. Thus, La(OH)3 is most basic whereas Lu(OH)3 is least basic.


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Which one of the following is an example of non-typical transition elements?

  • Li, K, Na

  • Be, Al, Pb

  • Zn, Cd, Hg

  • Ba, Ca, Sr


The d-block elements consists mostly of

  • mono-valent metals

  • all non-metals

  • elements which generally form stoichiometric metal oxide

  • many metals with catalytic properties


Which of the following properties increases on going down from F to I in group VII-A of the periodic table?

  • Electronegativity

  • Volatile nature

  • Ionic radius

  • Oxidising power


E°= -0.44V for the reaction, Fe2+ + 2e- → Fe and E°= -0.76 V for the reaction, Zn2+ + 2e- → Zn. Which of the following statement is correct?

  • Fe is more electropositive

  • Zn is more electropositive

  • Zn is more electronegative

  • None of the above


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Point out in which of the following properties oxygen differs from the rest of the members of its family (Group-VIA)?

  • High value of ionisation energies

  • Oxidation states (2,4,6)

  • Polymorphism

  • Formation of hydrides


The oxidation state of oxygen is zero in

  • CO

  • O3

  • SO2

  • H2O2


Four successive members of the first row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest third ionisation enthalpy? 

  • Vanadium (Z = 23)

  • Manganese (Z = 25)

  • Chromium (Z= 24)

  • Iron (Z = 26)


Which element from group V gives most basic compound with hydrogen?

  • Nitrogen

  • Bismuth

  • Arsenic

  • Phosphorus


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Which ion is colourless?

  • Cr4+

  • Sc3+

  • Ti3+

  • V4+


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