When aqueous AgNO3 and aqueous NaCl compounds are mixed together, there is a high chance of giving a white colour precipitate if initial silver nitrate and initial sodium chloride concentrations are considerably high. That means, AgNO3 and NaCl is a precipitation reaction. In this tutorial, we will learn about different aspects of this reaction such as precipitating and required concentrations for precipitation.
AgNO3(aq) + NaCl(aq) = AgCl(s) + NaNO3(aq)
Both silver nitrate and sodium chloride solutions are colourless solutions. When they react with each other, white precipitate and colourless solution is given. Sodium nitrate is colourless water soluble compound.
Observations during the reaction
When you are slowly adding one chemical to other chemical drop by drop, at one time, you will see a white precipitate is formed in the solution. If you immediately add one chemical to another, precipitate is also formed immediately. But, remember that to be careful with silver nitrate and during the experiment nitrate because it is a very toxic chemical .
Required concentration to see the precipitation
When similar volumes of NaCl and AgNO3 are mixed, will there be a precipitate? Both solutions have concentrations of 0.1 mol dm-3.
Let’s think, when both solutions are mixed, there is no precipitate and then calculate concentration of each compound. Because each compound is diluted by two times, concentration of NaCl and AgNO3 is reduced by half.
Then each compound has the concentration of 0.05 mol dm-3.
Then we can apply Ksp expression to check whether will there be a AgCl precipitate.
Initial Cl- concentration after mixing = 0.05 mol dm-3
Initial Ag+ concentration after mixing = 0.05 mol dm-3
Ksp expression for AgCl = [Ag+(aq)][Cl-(aq)]
[Ag+(aq)][Cl-(aq)] = 0.05 mol dm-3 * 0.05 mol dm-3
[Ag+(aq)][Cl-(aq)] = 2.5 * 10-3 mol2 dm-6
Ksp, AgCl = 1.7 * 10-10 mol2 dm-6
Because calculated value for Ksp expression is greater than Ksp value of AgCl. Therefore you can see AgCl is precipitated in the solution.
pH of NaCl and AgNO3 reaction
Both NaCl and AgNO3 are neutral solutions. The products of the reaction are AgCl and NaNO3. AgCl is a precipitate and does not cause for hydrolysis reaction. Also, NaNO3 is a neutral compound. Therefore, final solution should have a pH value close to 7.
Questions asked by students
Ask your question and find the answer free.
As silver nitrate, what are the other inorganic compounds which can also give a white precipitate with sodium nitrate?
Lead nitrate gives white precipitate with sodium nitrate and relevant reaction is given below.
Pb(NO3)2 + NaCl → PbCl2 + NaNO3
Instead of aqueous NaCl, what will happen if solid NaCl is added to aqueous AgNO3 is added?
In that case too, AgCl precipitate is given because when solid NaCl dissolved very well in water and dissociates to Na+ and Cl- ions. Then Cl- ion combines with Ag+ ions and give AgCl white precipitate.
What is the colour of the precipitate given by the AgNO3 and NaCl reaction? Also, will a gas will be released in this reaction?
AgCl is a white precipitate and there is no emission of gas during the reaction.
FeCl2 + NaOH reaction Reaction of cold and hot NaOH + Cl2 Solubility of metal hydroxides