Question

Consider the reaction :
$ H_2 SO_3 (aq) + Sn^{4+} (aq) + H_2 O(l) \rightarrow Sn^{2+} (aq) + HSO^{-}_4 (aq) + 3H^{+} (aq) $
Which of the following statements is correct?

• A. $Sn^{4+}$ is the oxidizing agent because it undergoes oxidation
• B. $Sn^{4+}$ is the reducing agent because it undergoes oxidation
• C. $H_2SO_3$ is the reducing agent because it undergoes oxidation
• D. $H_2SO_3$ is the reducing agent because it undergoes reduction

Answer 1

Answer: (C)

$H_{2} ^{+4}SO_{3} \left(aq\right)+sn^{4+}\left(aq\right)+H_{2}O\left(l\right) \to sn^{2+}\left(aq\right)+HS^{+6}O_{4} ^{-}\left(aq\right)+3H^{+}$
Hence $H_{2}SO_{3}$ is the reducing agent because it undergoes oxidation.