Na₂HPO₄ + NaOH → Na₃PO₄ + H₂O
Here's a breakdown:
* Disodium phosphate (Na₂HPO₄) is a weak base, meaning it can accept protons (H⁺).
* Sodium hydroxide (NaOH) is a strong base, meaning it readily donates hydroxide ions (OH⁻).
* The reaction produces trisodium phosphate (Na₃PO₄), which is a more soluble phosphate salt, and water (H₂O).
Essentially, the hydroxide ions from sodium hydroxide deprotonate the disodium phosphate, forming the more basic trisodium phosphate.
Important notes:
* The reaction is exothermic, meaning it releases heat.
* The pH of the solution will increase as the reaction progresses, becoming more alkaline.
* The resulting solution will contain a mixture of phosphate ions (PO₄³⁻) and hydroxide ions (OH⁻).
Uses:
This reaction is used in various applications, including:
* Cleaning: Trisodium phosphate is a common ingredient in cleaning products.
* Water treatment: It is used to adjust the pH of water and to remove heavy metals.
* Food industry: Trisodium phosphate is used as a food additive, for example, as a stabilizer in processed cheese.
Safety:
Both sodium hydroxide and trisodium phosphate are caustic and can cause skin and eye irritation. Always handle these chemicals with care and follow appropriate safety precautions.
