Silver Chloride Precipitation

AgNO3 + NaCl → AgCl↓ + NaNO3

Overview

Silver nitrate reacts with sodium chloride to form a white curdy precipitate of silver chloride. AgCl has a very low Ksp of 1.8 × 10⁻¹⁰, making it essentially insoluble. The precipitate turns purple in light due to photodecomposition of AgCl to silver metal and chlorine. This is the basis of the chloride ion test.

Participants

Role Substance Coefficient State
Reactant Silver Nitrate AgNO₃ 1 (aq)
Reactant Sodium Chloride NaCl 1 (aq)
Product Silver Chloride AgCl 1 (s)
Product Sodium Nitrate NaNO₃ 1 (aq)

Everyday Example

The silver chloride test for chloride ions in water is one of the first qualitative analysis tests taught in chemistry courses.

Industrial Importance

AgCl precipitation is used in water quality testing, photography (historical), and in the preparation of silver chloride electrodes for electrochemistry.

Properties

Type
Precipitation
Reversible
No
Energy
Exothermic
ΔH
-65.5 kJ/mol

Related Reactions

Aluminum Hydroxide Precipitation Barium Carbonate Precipitation Barium Sulfate Precipitation Cadmium Sulfide Precipitation (Yellow) Calcium Carbonate Precipitation Calcium Fluoride Precipitation (Fluorite) Calcium Oxalate Precipitation (Kidney Stones) Calcium Phosphate Precipitation (Bone Mineral) Calcium Sulfate Precipitation (Gypsum) Chromium(III) Hydroxide Precipitation

Frequently Asked Questions

What is the equation for Silver Chloride Precipitation?
The balanced equation is: AgNO₃ + NaCl → AgCl↓ + NaNO₃.
What type of reaction is Silver Chloride Precipitation?
Silver Chloride Precipitation is a precipitation reaction.
Is Silver Chloride Precipitation exothermic or endothermic?
Silver Chloride Precipitation is exothermic (releases energy). The enthalpy change (ΔH) is -65.5 kJ/mol.