S1 - Atoms (movement of particles) Flashcards
What three experiments can be used to show the movement of particles?
- Potassium Manganate(Vll) and water
- Ammonia and Hydrogen Chloride
- Bromine gas and air
Define the process evident in all three experiments
Diffusion - the movement of particles through a liquid or gas from an area of high concentration to an area of lower concentration until a uniform concentration is achieved
Describe the potassium manganate experiment with water
1) Get a beaker of water and place some potassium manganate at the bottom
2) Watch as the purple colour of the potassium manganate slowly spreads to fill the beaker - this is diffusion as the particles are diffusing out among the water particles
What causes the particles in the potassium manganate to eventually spread out evenly?
The random motion of particles in a liquid
What happens if you add more water to the final solution of the potassium manganate?
The potassium manganate would spread out even further apart and the solution would be less purple because of dilution
What does aqueous ammonia and hydrochloric acid give off?
Aqueous ammonia - ammonia gas
Hydrochloric acid - Hydrogen chloride gas
How should you set up the experiment with ammonia and hydrogen chloride?
In a glass tube have a cotton wool soaked in aqueous ammonia at one end and at the other, cotton wool soaked in hydrochloric acid.
What happens in the ammonia and hydrogen chloride experiment?
The ammonia gas diffuses from one end of the tube and the hydrochloric acid diffuses from the other. When they meet they react to form ammonium chloride (a white ring in the glass tube)
Why doesn’t the ring of ammonium chloride form in the middle?
If forms closest to the end of the tube where the hydrochloric acid was because the particles of ammonia are smaller and lighter than the hydrogen chloride, so diffuse through the air more quickly
What is bromine?
A brown gas that is very smelly
Describe the experiment using bromine gas?
Fill half a gas jar with bromide gas and the other with air - separate with gases with a glass plate. When you remove the glass plate watch how the bromide gas slowly diffuses through the air.
What causes the bromine to eventually diffuse right through the air?
The random motion of the particles
