What is the Difference Between Sodium Sulphate and Sodium Sulphite?

The key difference between sodium sulfate and sodium sulfite lies in their molecular structure, solubility, and boiling and melting points. Here are the main differences between the two compounds:

• Chemical Formula: Sodium sulfate has the chemical formula Na2SO4, while sodium sulfite has the chemical formula Na2SO3.
• Molecular Structure: Sodium sulfate has a different molecular structure than sodium sulfite due to the number of oxygen atoms in each compound.
• Solubility: Sodium sulfate is hygroscopic, meaning it absorbs moisture from the air. In contrast, sodium sulfite is less soluble in water compared to sodium sulfate.
• Boiling and Melting Points: Sodium sulfate has a melting point of 884°C and a boiling point of 1,429°C, while the boiling and melting points of sodium sulfite are not provided in the search results.
• Color Change with Acidified Potassium Dichromate: Sodium sulfite reacts with acidified potassium dichromate to reduce the dichromate to green chromium(III) ions, resulting in a color change from orange to green. Sodium sulfate does not produce this color change.

Both sodium sulfate and sodium sulfite are basic and can turn a pH indicator the same color. However, they have different properties and should not be used interchangeably in various applications, such as developer mixes in photography.

Comparative Table: Sodium Sulphate vs Sodium Sulphite

The main difference between sodium sulphate and sodium sulphite lies in the structure of their anions and their chemical formulas. Here is a comparison table highlighting the differences:

Both sodium sulphate and sodium sulphite are inorganic chemical compounds, but they have different properties and uses. Sodium sulphate is commonly used as a filler in the manufacturing of detergents, while sodium sulphite is primarily used in the pulp and paper industry as an antioxidant and preservative.