Redox Reactions

In the disproportionation reaction,

3HClO₃ → HClO₄ + Cl₂ + 2O₂ + H₂O

the equivalent mass of the oxidising agent is (molar mass of HClO₃ = 84.45)

• 16.89

• 32.22

• 84.45

• 28.15

To an aqueous solution containing anions a few drops of acidified KMnO₄ are added. Which one of the following anions, if present will not decolourise the KMnO₄ solution ?

• I^-

• CO${}_3^{2-}$

• S^2-

• NO${}_2^{-}$

In the following reaction,

M^x+ + MnO${}_4^{-}$ → MO${}_3^{-}$ + Mn²⁺ + $\frac{1}{2}$O₂

If one mole of MnO${}_4^{-}$ oxidises 2.5 moles of M^x+, then the value of x is

• 5

• 3

• 2

• 1

When MnO₂ is fused with KOH, a coloured compound is formed. The product and its colour is

• K₂MnO₄, purple green

• KMnO₄, purple

• Mn₂O₃, brown

• Mn₂O₄, black

Which of the following is the strongest reducing agent?

• HF

• HCl

• HI

• HBr