Question

Which of the following set is having correct statements?

$1.$ $H_{2}O_{2}$ is a weak base

$\text{2} \text{.} \, \text{H}_{\text{2}} \text{O}_{\text{2}}$ oxidizes Fe (II) to Fe (III)

$3.$ $H_{2}O_{2}$ can be obtained by the electrolysis of conc. $H_{2}SO_{4}$

$\text{4} \text{.} \, \text{H}_{\text{2}} \text{O}_{\text{2}}$ reduces Mn (VII) to Mn (II)

• A. 2, 3
• B. 3, 4
• C. 2, 3, 4
• D. 1, 2, 3, 4

Answer 1

Answer: (C)

Here statements 2, 3 and 4 are correct as follows

$H_{2}O_{2}$ is weakly acidic, but more acidic than water.

$H_{2}O_{2}+H_{2}O \rightarrow H_{3}O^{+}+HO_{2}^{-}$

$2Fe^{2 +}+H_{2}O_{2}+2H^{+} \rightarrow 2Fe^{3 +}+2H_{2}O$

$H_{2}SO_{4}\rightleftharpoons H^{+}+HSO_{4}^{-}$



The peroxy disulphuric acid is hydrolysed separately to get $H_{2}O_{2}$ .

$H_{2}S_{2}O_{8}+H_{2}O \rightarrow H_{2}SO_{5}+H_{2}SO_{4}$

$H_{2}SO_{5}+H_{2}O \rightarrow H_{2}SO_{4}+H_{2}O_{2}$

$2MnO_{4}^{-}+5H_{2}O_{2}+6H^{+} \rightarrow 2Mn^{2 +}+8H_{2}O+5O_{2}$