Dilute Acid Lab Bench
React dilute H2SO4 with metals and salts
What this lesson covers
Why it matters
Dilute sulphuric acid is a chameleon in the lab, releasing different gases depending on its partner.
The idea in plain words
Map the displacement: Zn takes SO₄, H becomes H₂ gas.
Predict first
What gas is released when zinc reacts with dilute sulphuric acid?
Zinc displaces hydrogen from the acid, producing hydrogen gas that burns with a pop.
- Oxygen
- Hydrogen — correct
- Sulphur dioxide
- Carbon dioxide
What you do
Test zinc, sodium carbonate, iron sulphide, and sodium sulphite with dilute H₂SO₄. Identify the gas in each case using the provided tests.
Check yourself
Which gas is identified by a 'pop' sound with a burning splinter?
Hydrogen burns explosively in air, producing a characteristic pop.
What is the observation when sodium carbonate reacts with dilute sulphuric acid?
Na₂CO₃ + H₂SO₄ → Na₂SO₄ + H₂O + CO₂. CO₂ turns limewater milky.
Which reaction produces hydrogen sulphide (H₂S)?
FeS + H₂SO₄ → FeSO₄ + H₂S. H₂S has a rotten-egg smell.
Sodium sulphite reacts with dilute sulphuric acid to release...
Na₂SO₃ + H₂SO₄ → Na₂SO₄ + H₂O + SO₂. SO₂ has a suffocating smell.
- Hydrogen — correct
- Carbon dioxide
- Sulphur dioxide
- Rotten egg smell
- Effervescence and gas turns limewater milky — correct
- Suffocating smell of burning sulphur
- Zn + H₂SO₄
- FeS + H₂SO₄ — correct
- Na₂SO₃ + H₂SO₄
- SO₂ with a suffocating smell of burning sulphur — correct
- SO₃ with a sweet smell
- O₂ with no smell