6 NaI (aq) + 2 Na2CrO4 (aq) + 5 H2SO4 (aq) → 5 Na2SO4 (aq) + 3 I2 (s) + Cr2O3 (s) + 5 H2O (l)

This is an acid-base reaction (neutralization): Na2CrO4 is a base, H2SO4 is an acid.

This is an oxidation-reduction (redox) reaction:

6 I-I - 6 e- → 6 I0 (oxidation)

2 CrVI + 6 e- → 2 CrIII (reduction)

NaI is a reducing agent, Na2CrO4 is an oxidizing agent.

This is a precipitation reaction: I2 andCr2O3 is the formed precipitate.

Reactants:

  • NaI
    • Names: Sodium iodide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Sodium iodide (anhydrous) source: ICSC, accessed: 2019-09-04, NaI source: wikidata, accessed: 2019-09-02, Sodium monoiodide source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Appearance: White solid | deliquescent source: wikipedia, accessed: 2019-09-27; Colourless-to-white hygroscopic crystals or white powder. turns brown on exposure to air source: ICSC, accessed: 2019-09-04
  • Na2CrO4 – Sodium chromate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Other names: Chromic acid source: wikipedia, accessed: 2019-09-27, (Na2CrO4) source: wikipedia, accessed: 2019-09-27, Disodium salt source: wikipedia, accessed: 2019-09-27
    • Appearance: Yellow crystals source: wikipedia, accessed: 2019-09-27; Yellow hygroscopic crystals source: ICSC, accessed: 2019-09-04
  • H2SO4 – Sulfuric acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Oil of vitriol source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Sulfuric acid, concentrated (> 51% and < 100%) source: ICSC, accessed: 2019-09-04, H2SO4 source: wikidata, accessed: 2019-09-07
    • Appearance: Clear, colorless liquid source: wikipedia, accessed: 2019-09-27; Odourless colourless oily hygroscopic liquid source: ICSC, accessed: 2019-09-04; Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51°F. Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02

Products:

  • Na2SO4
    • Names: Sodium sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Sodium sulphate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Sulfate of sodium source: wikipedia, accessed: 2019-09-27
    • Appearance: White crystalline solid | hygroscopic source: wikipedia, accessed: 2019-09-27; White hygroscopic solid in various forms source: ICSC, accessed: 2019-09-04
  • I2
    • Names: Iodine source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Jod source: ICSC, accessed: 2019-09-04, Iode source: ICSC, accessed: 2019-09-04
    • Appearance: Bluish black or dark purple crystals with pungent odour source: ICSC, accessed: 2019-09-04; Violet solid with a sharp, characteristic odor. source: NIOSH NPG, accessed: 2019-09-02
  • Cr2O3
    • Names: Chromium(III) oxide source: wikipedia, accessed: 2019-09-27, Chromium sesquioxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Chromia source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Appearance: Light to dark green, fine crystals source: wikipedia, accessed: 2019-09-27; Light-to-dark-green powder source: ICSC, accessed: 2019-09-04
  • H2O – Water, oxidane source: wikipedia, accessed: 2019-09-27
    • Other names: Water (H2O) source: wikipedia, accessed: 2019-09-27, Hydrogen hydroxide (HH or HOH) source: wikipedia, accessed: 2019-09-27, Hydrogen oxide source: wikipedia, accessed: 2019-09-27
    • Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas source: wikipedia, accessed: 2019-09-27