Practical work 3: ammonia
Answers are for parents and teachers.
1
In 2NH₃ + H₂SO₄ → (NH₄)₂SO₄, how many grams of salt form from 34 g NH₃ and 98 g H₂SO₄?
132 g
2
In 3NH₃ + H₃PO₄ → (NH₄)₃PO₄, how many mol H₃PO₄ are needed for 6 mol NH₃?
2 mol
3
If more ammonia is added to NH₃ + H₂O ⇌ NH₄⁺ + OH⁻, which way does equilibrium shift?
To the right (NH₄⁺ and OH⁻ increase).
4
Make a plan: how would you tell two tubes, NH₄Cl and NaCl, apart with alkali (without smelling)?
The teacher adds NaOH to each and warms; the gas from NH₄Cl turns moist red litmus blue.
5
Why is it recommended to do the ammonia experiment only in a fume cupboard?
Ammonia burns airways and eyes; the cupboard carries the gas away.