Testing Anions - Nitrates
Chemistry: Cambridge International GCSE Supplement, topic 12.5.7
Testing for Nitrates
We can test for nitrate ions (NO3-) by reducing them to ammonia.
Process
- Add sodium hydroxide solution, then aluminium powder or foil.
- Heat strongly.
Positive result
- If nitrate ions are present, ammonia gas is given off.
- Ammonia gas turns damp red litmus paper blue. It also gives off a distinctive cooking smell.
Test yourself on Testing Anions - Nitrates
What is the chemical formula of nitrate ions?
Testing for Nitrates
Which of these are needed in testing for nitrate ions?