The Orange colour of Cr₂O₇^2– ion changes to yellow when treated with an
alkali. Why ?

Chemistry of actinoids is complicated as compared to lanthanoids. Give two reasons.

Complete and balance the following chemical equations :

$F{e}^{2+} + Mn{O}_4^{-} + H^{+} \stackrel{ }{\to }$

Complete and balance the following chemical equation:

$Mn{O}_4^{-} + H_{2}O + I^{-} \stackrel{ }{\to }$

Give reason:

E° value for a Mn³⁺/Mn²⁺ couple is much more positive than that for Fe3⁺/Fe²⁺.

366.

Give reason:

Iron has a higher enthalpy of atomization than that of copper.

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