The correct statement is

• The earlier members of lanthanoid series resemble calcium in their chemical properties.

• The extent of actinoid contraction is almost the same as lanthanoid contraction.

• In general, lanthanoid and actinoids do not show variable oxidation states.

• Ce⁴⁺ in aqueous solution is not known.

532.

The electronic configuration of Gd²⁺ is (atomic number of Gd is 64).

• [Xe]4f⁸

• [Xe]4f⁷

• [Xe]4f⁷ 5d¹6s²

• [Xe]4f⁷ 5d¹

The composition of "copper matte" is

• Cu₂S + FeS

• Cu₂S + Cu₂O

• Cu₂S + FeO

• Cu₂O + FeS

The bivalent metal ion having maximum paramagnetic behaviour among the first transition series elements is

• Mn²⁺

• Cu²⁺

• Sc²⁺

• Cu⁺

When a brown compound of Mn (A) is treated with HCl, it gives a gas (B). The gas (B) taken in excess reacts with NH₃ to give; an explosive compound (C). The compounds A, B and C respectively are

• A - MnO₂; B - Cl₂; C - NCl₃

• A - MnO; B - Cl₂; C - NH₄Cl

• A - Mn₃O₄; B - Cl₂; C - NCl₃

• A - MnO₃; B - Cl₂; C - NCl₂

Mn²⁺ compounds are more stable than Fe²⁺ compounds towards oxidation to their +3 state, because

• Mn²⁺ is more stable with high 3^rd ionisation energy

• Mn²⁺ is bigger in size

• Mn²⁺ has completely filled d-orbital

• Mn²⁺ does not exist

The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition elements which shows highest magnetic moment?

• 3d⁷

• 3d⁸

• 3d⁵

• 3d²

Which of the following statement is wrong regarding lanthanoids?

• Ln(III) compounds are predominantly ionic in character.

• Ln(III) compound are generally colourless

• Ln(III) hydroxide are mainly basic in nature

• The ionic size of Ln(III) ions decreses with increasing atomic number.

For d block elements the first ionization potential is of the order :

• Zn > Fe > Cu > Cr

• Sc = Ti < V = Cr

• Zn < Cu < Ni < Co

• V > Cr > Mn > Fe

Fe²⁺ ion is distinguished from Fe³⁺ ion by :

• BaCl₂

• KCN

• NaNO₃

• NH₄SCN