Two metals that evolve hydrogen gas when they react with dilute nitric acid are magnesium (Mg) and manganese (Mn).
1. Magnesium (Mg) with dilute nitric acid:
- Reaction:
Mg(s) + 2HNO₃(aq) → Mg(NO₃)₂) + H₂(g)
2. Manganese (Mn) with dilute nitric acid:
- Reaction:
Mn(s) + 2HNO₃(aq) → Mn(NO₃)₂) + H₂(g)
These metals are able to reduce nitric acid under certain conditions, leading to the evolution of hydrogen gas.
Hydrogen Gas Test: The Squeaky Pop Test
Procedure:
- Bring the splint near the gas: Carefully bring the lighted splint to the mouth of the test tube containing the gas.
- Collect the gas: Collect the gas you suspect is hydrogen in a test tube.
- Prepare a lighted splint: Ignite a wooden splint.
Hydrogen gas is highly flammable. When it comes into contact with a flame, it reacts rapidly with oxygen in the air, releasing energy in the form of a small explosion. This explosion causes the characteristic “pop” sound.
Caution: Hydrogen gas is highly flammable. Always handle it with care and in a well-ventilated area. Perform this test in the presence of Experts