The pair in which phosphorous atoms have a formal oxidation state of +3 is:

• Pyrophosphorous and hypophosphoric acids

• Orthophosphorous and hypophosphoric acids

• Pyrophosphorous and pyrophosphoric acids

• Pyrophosphorous and pyrophosphoric acids

Which among the following is the most reactive?

• Cl₂

• Br₂

• I₂

• I₂

Match the catalysis to the correct processes.

• (A)- (iii), (B)-(ii), (C)-iv, (D)- (i)

• (A) - (ii), (B) - (i), (C) -(iv), (D) - (iii)

• (A)- (ii), (B)- (iii), (C)- (iv), (D) - (i)

• (A)- (ii), (B)- (iii), (C)- (iv), (D) - (i)

The equation which is balanced and represents the correct product(s) is

• Li₂O + 2KCl → 2LiCl + K₂O

• [COCl(NH₃)₅]⁺ + 5H⁺ → Co²⁺

• [Mg(H₂O)₆]²⁺ + (EDTA)^4-  [Mg(EDTA)]²⁺ + 6H₂O

• [Mg(H₂O)₆]²⁺ + (EDTA)^4-  [Mg(EDTA)]²⁺ + 6H₂O

Which of the following arrangements does not represent the correct order of the property stated against it?

• V²⁺ < Cr²⁺<Mn²⁺<Fe²⁺: paramagnetic behaviour

• Ni²⁺ < Co²⁺ < Fe²⁺ < Mn²⁺ ; Ionic size

• Co³⁺ < Fe³⁺< Cr³⁺ < Sc³⁺ : stability in aqueous solution

• Co³⁺ < Fe³⁺< Cr³⁺ < Sc³⁺ : stability in aqueous solution

Iron exhibits + 2 and +3 oxidation states. Which of the following statements about iron is incorrect?

• Ferrous oxide is more basic in nature than the ferric oxide.

• Ferrous compounds are relatively more ionic than the corresponding ferric compounds.

• Ferrous compounds are less volatile than the corresponding ferric compounds.

• Ferrous compounds are less volatile than the corresponding ferric compounds.

The correct order of E°_M2+/M values with negative sign for the four successive elements Cr, Mn, Fe and Co is

• Cr > Mn > Fe > Co

• Mn > Cr > Fe > Co

• Cr > Fe > Mn > Co

• Cr > Fe > Mn > Co

Sodium salt of an organic acid 'X' produces effervescence with conc. H₂SO₄. 'X' reacts with the acidified aqueous CaCl2 solution to give a white precipitate which decolourises acidic solution of KMnO₄. 'X' is

• C₆H₅COONa

• HCOONa

• Na₂C₂O₄

• Na₂C₂O₄

Knowing that the Chemistry of lanthanoids (Ln) is dominated by its +3 oxidation state, which of the following statements in incorrect

• The ionic sizes of Ln (III) decrease in general with increasing atomic number.

• Ln (III) compounds are generally colourless.

• Because of the large size of the Ln (III) ions, the bonding in its compounds is predominantly ionic in character

• Because of the large size of the Ln (III) ions, the bonding in its compounds is predominantly ionic in character

In context with the transition elements, which of the following statements is incorrect?

• In addition to the normal oxidation states, the zero oxidation state is also shown by these elements in complexes.

• In the highest oxidation states, the transition metal shows basic character and form cationic complexes.

• In the highest oxidation states of the first five transition elements (Sc to Mn), all the 4s and 3d electrons are used for bonding.

• In the highest oxidation states of the first five transition elements (Sc to Mn), all the 4s and 3d electrons are used for bonding.