Sum of – bonds present in peroxodisulphuric acid and pyrosulphuric acid is __________
Show answer and solution
Answer: 8
Solution
Peroxodisulphuric acid (H₂S₂O₈): Structure has two SO₄ units linked by a peroxide (-O-O-) bond. Each S has 3 S=O bonds (one S-OH, two S=O, and one S-O-O), giving 3 π-bonds per S atom × 2 = 6 π-bonds total.
Pyrosulphuric acid (H₂S₂O₇): Structure has two SO₃ units linked by a bridging oxygen (-S-O-S-). Each S has 3 S=O bonds (two S=O and one S-OH), giving 3 π-bonds per S × 2 = 6 π-bonds... wait.
Let me recount carefully:
H₂S₂O₈ (peroxodisulphuric acid): Each S is bonded to 2 =O, 1 -OH, 1 -O-O-. So 2 π-bonds per S × 2 S = 4 π-bonds.
H₂S₂O₇ (pyrosulphuric acid): Each S is bonded to 2 =O, 1 -OH, 1 -O- (bridging). So 2 π-bonds per S × 2 S = 4 π-bonds.
Sum = 4 + 4 = 8 π-bonds.
The key point: In each acid, every S atom forms 2 S=O (π) bonds; the -OH and bridging oxygens (including peroxide) carry no π character. With 2 sulfur atoms in each molecule contributing
Pyrosulphuric acid (H₂S₂O₇): Structure has two SO₃ units linked by a bridging oxygen (-S-O-S-). Each S has 3 S=O bonds (two S=O and one S-OH), giving 3 π-bonds per S × 2 = 6 π-bonds... wait.
Let me recount carefully:
H₂S₂O₈ (peroxodisulphuric acid): Each S is bonded to 2 =O, 1 -OH, 1 -O-O-. So 2 π-bonds per S × 2 S = 4 π-bonds.
H₂S₂O₇ (pyrosulphuric acid): Each S is bonded to 2 =O, 1 -OH, 1 -O- (bridging). So 2 π-bonds per S × 2 S = 4 π-bonds.
Sum = 4 + 4 = 8 π-bonds.
The key point: In each acid, every S atom forms 2 S=O (π) bonds; the -OH and bridging oxygens (including peroxide) carry no π character. With 2 sulfur atoms in each molecule contributing
[JEE Main 2023 · 24 Jan · Shift 2]