Precipitate the Chloride
Identify Cl- ions using silver and lead nitrate
What this lesson covers
Why it matters
Pour silver nitrate into sodium chloride and watch the clear liquid turn milky white in seconds.
The idea in plain words
Observe the ionic swap: Ag⁺ pairs with Cl⁻ to drop out as solid AgCl, while Na⁺ and NO₃⁻ stay in solution.
Predict first
What happens when you mix these two clear solutions?
Chloride ions react with silver ions to form insoluble silver chloride, a classic white precipitate.
- The solution remains clear
- A white precipitate forms — correct
- The solution turns yellow
- Gas bubbles evolve
What you do
First, add silver nitrate to sodium chloride. Then, try lead nitrate with sodium chloride. Compare the white solids formed.
Check yourself
Which equation correctly represents the reaction between silver nitrate and sodium chloride?
Silver nitrate and sodium chloride undergo double decomposition to form insoluble silver chloride and soluble sodium nitrate.
Why is this reaction a positive test for chloride ions?
The formation of the characteristic white precipitate of silver chloride (AgCl) confirms the presence of chloride ions.
What is the product formed when lead nitrate reacts with sodium chloride?
Lead nitrate reacts with sodium chloride to form insoluble lead(II) chloride (PbCl₂) and sodium nitrate.
- AgNO₃ + NaCl → AgCl + NaNO₃ — correct
- AgNO₃ + NaCl → AgCl₂ + NaNO₃
- 2AgNO₃ + NaCl → Ag₂Cl + NaNO₃
- AgNO₃ + NaCl → No Reaction
- Because it produces a white precipitate of AgCl — correct
- Because it produces a white precipitate of NaNO₃
- Because the solution turns blue
- Because it releases chlorine gas
- PbCl₂ and NaNO₃ — correct
- PbCl and NaNO₃
- Pb(NO₃)₂ and NaCl
- PbO and NaCl