A teacher uses an apparatus to demonstrate the reaction between ammonia gas and hydrogen bromide gas to form solid ammonium bromide.
The reaction is represented by the equation: NH3(g)+HBr(g)→NH4Br(s)\text{NH}_3(\text{g}) + \text{HBr}(\text{g}) \rightarrow \text{NH}_4\text{Br}(\text{s})NH3(g)+HBr(g)→NH4Br(s)
Which process occurs when the gas particles move along the tube?
- A: condensation
- B: diffusion
- C: sublimation
- D: vaporisation
Explain how the diagram shows which gas moves more quickly during the experiment.
The teacher then tests a sample of ammonium bromide solution.
To show that the sample contains ammonium ions, they perform the following test:
- Add solution X
- Warm the mixture
- Test the gas given off with damp red litmus paper
Suggest the identity of solution X, the identity of the gas given off, and the final colour of the litmus paper.
To show that the sample contains bromide ions, they perform the following test:
- Add dilute nitric acid
- Add solution Y
- Observe the formation of a cream precipitate
Why is dilute nitric acid added first?
Suggest the identities of solution Y and the cream precipitate.