Question
What is the stoichiometric coefficient of SO _2 in the following balance reaction? MnO _4^ - (a q)+ SO _2(g) Mn ^ 2+ (a q)+ HSO _4^ - (a q) (in acidic solution)
BITSAT
Chemistry
Redox Reactions
2024
BITSAT 2024 (Memory Based Paper 3)
BITSAT Chemistry Question (2024) — Solution
Options
- A. 5
- B. 4
- C. 3
- D. 2
Answer
A. 5
Step-by-step solution
Oxidation half reaction: SO _2( ~g )+2 H _2 O (l) HSO _4^ - (a q)+3 H ^ + (a q)+2 e^ - ...(i) Reduction half reaction: MnO _4^ - (a q)+8 H ^ + +5 e^ - Mn ^ 2+ (a q)+4 H _2 O (l)...(ii) Multiply eq. (i) by 5 and (ii) by 2 and then add aligned 2 MnO _4^ - (a q)+5 SO _2(g) & +2 H _2 O (l)+ H ^ + (a q) \\ & 2 Mn ^ + (a q)+5 HSO _4^ - (a q) aligned Thus, the stoichiometric coefficient of SO _2 in the above balance equation is 5 .
Related: Chemistry — Redox Reactions · All PYQ Banks