2 K₂CrO₄ (aq) + H₂SO₄ (aq) → K₂Cr₂O₇ (aq) + K₂SO₄ (aq) + H₂O (l)

This is an acid-base reaction (neutralization): K₂CrO₄ is a base, H₂SO₄ is an acid.

Reactants:

K₂CrO₄ – Potassium chromate
- Other names: Chromic acid , (K2CrO4) , Dipotassium salt
- Appearance: Yellow powder ; Yellow crystals
H₂SO₄ – Sulfuric acid
- Other names: Oil of vitriol , Sulfuric acid, concentrated (> 51% and < 100%) , H2SO4
- Appearance: Clear, colorless liquid ; Odourless colourless oily hygroscopic liquid ; Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51°F. Often used in an aqueous solution.]

Products:

K₂Cr₂O₇ – Potassium dichromate(VI)
- Other names: Potassium dichromate , Chromium potassium oxide , Dipotassium dichromium heptaoxide
- Appearance: Red-orange crystalline solid ; Orange-to-red crystals
K₂SO₄
- Names: Potassium sulfate , Potassium sulphate , Dipotassium sulfate
- Appearance: White solid ; Colourless-to-white crystals
H₂O – Water, oxidane
- Other names: Water (H2O) , Hydrogen hydroxide (HH or HOH) , Hydrogen oxide
- Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas

2 K2CrO4 (aq) + H2SO4 (aq) → K2Cr2O7 (aq) + K2SO4 (aq) + H2O (l)