In a transition series, with increase in atomic-number, the paramagnetism

• increases gradually

• decreases gradually

• first increases to a maximum and then decreases

• first decreases to a minimum and then increases

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 composition of "copper matte" is

• Cu₂S + FeS

• Cu₂S + Cu₂O

• Cu₂S + FeO

• Cu₂O + FeS

The electronic configuration of Cu²⁺ ion is

• [Ar] 3d⁸ 4s¹

• [Ar] 3d⁹ 4s⁰

• [Ar] 3d⁷ 4s²

• [Ar] 3d⁸ 4s⁰

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

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

• [Xe]4f⁸

• [Xe]4f⁷

• [Xe]4f⁷ 5d¹6s²

• [Xe]4f⁷ 5d¹

Which of the following is a negatively charged bidentate ligand?

• Cyano

• Ethylene diamine

• Acetato

• Dimethyl glyoximato

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

• Mn²⁺

• Cu²⁺

• Sc²⁺

• Cu⁺

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.

Which one of the following shows highest magnetic moment?

• Fe²⁺

• Co²⁺

• Cr³⁺

• Ni²⁺