d- and f-Block Elements

NEET 2013 (Karnataka)MCQEasyNot asked in last 5 yrs+4−1

Ques. 1NEET 2013 (Karnataka)

Sc (Z = 21) is a transition element but Zn (Z = 30) is not because

both Sc3+ and Zn2+ ions are colourless and form white compounds.
in case of Sc, 3d orbitals are partially filled but in Zn these are filled.
last electron is assumed to be added to 4s level in case of Zn.
both Sc and Zn do not exhibit variable oxidation states.

Answer

(2) in case of Sc, 3d orbitals are partially filled but in Zn these are filled.

Solution

As per NCERT, transition elements are those which have incompletely filled d orbitals in the ground state or in any of their common oxidation states.

Sc: [Ar] 3d1 4s2 ⇒ 3d partially filled ⇒ transition element.

Zn: [Ar] 3d10 4s2 and Zn2+: 3d10 ⇒ 3d completely filled ⇒ not a transition element.

Answer: (2)

Keep practising — d- and f-Block Elements

Ques. 2AIPMT 2012 (Mains)

The catalytic activity of transition metals and their compounds is ascribed mainly to

their magnetic behaviour
their unfilled d-orbitals
their ability to adopt variable oxidation states
their chemical reactivity

Ques. 3AIPMT 2012 (Mains)

Which of the following exhibits only + 3 oxidation state?

Ques. 4AIPMT 2012 (Mains)

Which one of the following does not correctly represent the correct order of the property indicated against it?

Ti < V < Cr < Mn : increasing number of oxidation states
Ti3+ < V3+ < Cr3+ < Mn3+ : increasing magnetic moment
Ti < V < Cr < Mn : increasing melting points
Ti < V < Mn < Cr : increasing 2nd ionization enthalpy

Ques. 5AIPMT 2012 (Mains)

Four successive members of the first series of the transition metals are listed below. For which one of them the standard potential ( E M2+/M ) value has a positive sign?

Co (Z = 27)
Ni (Z = 28)
Cu (Z = 29)
Fe (Z = 26)

Ques. 6AIPMT 2012 (Prelims)

Identify the alloy containing a non-metal as a constituent in it.

Invar
Steel
Bell metal
Bronze

Ques. 7AIPMT 2012 (Prelims)

Which of the statements is not true?

On passing H2S through acidified K2Cr2O7 solution, a milky colour is observed.
Na2Cr2O7 is preferred over K2Cr2O7 in volumetric analysis.
K2Cr2O7 solution in acidic medium is orange.
K2Cr2O7 solution becomes yellow on increasing the pH beyond 7.

Ques. 8AIPMT 2011 (Prelims)

For the four successive transition elements (Cr, Mn, Fe and Co), the stability of +2 oxidation state will be there in which of the following order? (At. nos. Cr = 24, Mn = 25, Fe = 26, Co = 27)