Determination of Concentration of Silver Nitrate by Mohrʼs Method

Aim: Determination of Concentration of Silver Nitrate by Mohrʼs Method

Determine the concentration of silver nitrate using the standard solution of sodium chloride.

Determination of Concentration of Silver Nitrate by Mohrʼs Method

Mohr’s method.

Objectives: Determination of Concentration of Silver Nitrate by Mohrʼs Method

• <p>Understands Mohr&rsquo;s method.

• Analyze silver nitrate solution by following Mohr&rsquo;s method.</p>

Background: Determination of Concentration of Silver Nitrate by Mohrʼs Method

Precipitimetry: It is a volumetric method of analysis that involves the formation of a practically insoluble salt using a precipitating agent.

Solubility product (Ksp): In a saturated solution of a sparingly soluble electrolytes, the product of molar concentration of ions each raised to a power equal to the number of ions produced is constant at room temperature and pressure.
 
 

Ksp of AnBm =[A]n[B]m

 
N.B: Substance with low Ksp precipitate first.
 
Conditions required for a precipitimetry reactions:
The precipitate must be practically insoluble.
Rapid precipitation.
Ease of detection of the endpoint.

Principle: Determination of Concentration of Silver Nitrate by Mohrʼs Method

Direct argentometry.
In neutral or slightly alkaline medium, sodium chloride is titrated with silver nitrate (AgNO3) forming silver chloride precipitate using n-chromate as indicator.
NaCl + AgNO3NaNO3 +AgCl

After precipitation of all chloride, the first drop excess of AgNO3 will react with n-chromate forming: Ag2CrO4 reddish brown precipitate. (Endpoint).