8 NaOH (aq) + 4 S (s) → 4 H₂O (l) + Na₂SO₄ (aq) + 3 Na₂S (aq)

This is an oxidation-reduction (redox) reaction:

S is both an oxidizing and a reducing agent (disproportionation (dismutation)).

Reactants:

• NaOH
  • Names: Sodium hydroxide , Caustic soda , Lye ... show moreSoda lye , Sodium hydrate , NaOH , White caustic , Lye [Sodium hydroxide] show less
  • Appearance: White, waxy, opaque crystals ; White hygroscopic solid in various forms ; Colorless to white, odorless solid (flakes, beads, granular form).
• S
  • Names: Sulfur , S , Sulphur ... show moreElement 16 , Flowers of sulfur , Flour sulfur , Brimstone show less
  • Appearance: Yellow solid in various forms

Products:

• H₂O – Water, oxidane
  • Other names: Water (H2O) , Hydrogen hydroxide (HH or HOH) , Hydrogen oxide ... show moreDihydrogen monoxide (DHMO) (systematic name) , Hydrogen monoxide , Dihydrogen oxide , Hydric acid , Hydrohydroxic acid , Hydroxic acid , Hydrol , Μ-oxido dihydrogen , Κ1-hydroxyl hydrogen(0) show less
  • Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas
• Na₂SO₄
  • Names: Sodium sulfate , Sodium sulphate , Sulfate of sodium ... show moreThenardite (mineral) , Glauber's salt (decahydrate) , Sal mirabilis (decahydrate) , Mirabilite (decahydrate mineral) , Disodium sulfate , Anhydrous sodium sulfate , Sodium sulfate anhydrous , Sodium sulfate, anhydrous , Sodium sulphate anhydrous , Sodium sulphate, anhydrous , Sulfuric acid disodium salt, anhydrous , Disodium sulphate , Salt cake , Na2SO4 , Sulfuric acid disodium salt show less
  • Appearance: White crystalline solid | hygroscopic ; White hygroscopic solid in various forms
• Na₂S
  • Names: Sodium sulfide , Disodium sulfide , Sodium sulfide (anhydrous) ... show moreSodium monosulfide , Sodium sulphide show less
  • Appearance: Colorless, hygroscopic solid ; White-to-yellow hygroscopic crystals with characteristic odour