Ammonium Salt Test
Detect ammonium ions with heat and NaOH.
What this lesson covers
Why it matters
Heat a mixture of ammonium chloride and sodium hydroxide, and a pungent gas escapes that turns red litmus blue.
The idea in plain words
Verify the balanced equation: NH₄Cl + NaOH → NaCl + H₂O + NH₃.
Predict first
What gas is released when ammonium salts are heated with a strong base like NaOH?
Ammonium ions react with hydroxide ions to form water and ammonia gas.
- Hydrogen chloride (HCl)
- Ammonia (NH₃) — correct
- Nitrogen (N₂)
- Oxygen (O₂)
What you do
Heat the mixture. Observe the gas evolution and test it with moist red litmus paper.
Check yourself
How do you confirm the gas is ammonia?
Ammonia is alkaline; it turns moist red litmus paper blue.
Why is heat required for this reaction?
Heating provides the energy needed to drive the double decomposition reaction forward.
What is the nature of the gas produced?
Ammonia dissolves in water to form ammonium hydroxide, which is alkaline.
- It relights a glowing splint
- It turns moist red litmus blue — correct
- It turns moist blue litmus red
- It produces a pop sound
- To melt the sodium hydroxide
- To provide activation energy for the decomposition — correct
- To evaporate the water produced
- To break the ionic bonds in NaCl
- Acidic
- Neutral
- Alkaline — correct
- Oxidizing