Hyposulfite

Not to be confused with hydrosulfite, which is another name for the dithionite anion (S
₂O²⁻
₄).

Hyposulfite may refer to:

• The sulfoxylate anion (SO²⁻
  ₂)
• The thiosulfate anion (S
  ₂O²⁻
  ₃)
  • Sodium thiosulfate, a salt containing the thiosulfate anion
• S
  ₂O²⁻
  ₂, a reported sulfur oxyanion. However salts containing S
  ₂O²⁻
  ₂ and HS
  ₂O⁻
  ₂ are not well characterized; they would be conjugate bases derived from the parent thiosulfurous acid (H
  ₂S
  ₂O
  ₂), which is also of doubtful existence.^[1]
• Dithionite (S
  ₂O²⁻
  ₄) as in sodium dithionite.^[2]