2 NaOH + (NH4)2SO4 → 2 NH3 + Na2SO4 + 2 H2O

This is an acid-base reaction (neutralization): NaOH is a base, (NH4)2SO4 is an acid.

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).
• (NH4)2SO4 – Ammonium tetraoxosulfate (VI)
  • Other names: Ammonium sulphate , Ammonium sulfate , Ammonium sulfate (2:1) ... show moreDiammonium sulfate , Sulfuric acid diammonium salt , Mascagnite , Actamaster , Dolamin , (NH4)2SO4 , Sulfuric acid, diammonium salt , Sulfuric acid ammonium salt (1:2) show less
  • Appearance: Fine white hygroscopic granules or crystals.

Products:

• NH3
  • Names: Ammonia , Azane (only intended for use in naming derivatives of ammonia) , Hydrogen nitride ... show moreAmmonia (anhydrous) , Azane , NH3 , Trihydrogen nitride , R717 , Refrigerant gas 717 , Anhydrous ammonia , Aqua ammonia , Aqueous ammonia , [Note: Often used in an aqueous solution.] show less
  • Appearance: Colourless gas ; Colourless gas or compressed liquefied gas with pungent odour ; Colorless gas with a pungent, suffocating odor. [Note: Shipped as a liquefied compressed gas. Easily liquefied under pressure.]
• 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
• 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