Movement of Particles

Question 1

What is diffusion?

Answer 1

-The movement of particles through a liquid or gas
-The gradual movement of particles from places
-The natural tendency for stuff to spread out

Question 2

Why is Potassium Manganate (VII) good for a experiment demonstrating diffusion?

Answer 2

Because its bright purple

Question 3

Method: Potassium Manganate (VII) and Water

Answer 3

1. Take a beaker of water and place some potassium manganate (VII) at the bottom -> purple colour slowly spreads out to fill the beaker
2. The particles of potassium manganate (VII) are diffusing out among the particles of water
3. Its the random motion of particles in a liquid -> causes the purple colour to eventually be evenly spread out throughout the water

Question 4

What would happen if you were to add more water to the final purple solution?

Answer 4

The potassium manganate (VII) particles would spread even further apart & the solution would be less purple -> called DILUTION

Question 5

What gas does aqueous ammonia give off?

Answer 5

Ammonia gas (NH3)

Question 6

What gas does hydrochloric acid give off?

Answer 6

Hydrogen chloride gas (HCL)

Question 7

What forms when ammonia gas & hydrogen chloride meet?

Answer 7

A white ring of ammonium chloride forms in the glass tube

Question 8

What do NH3 gas & HCL gas form when they diffuse from opposite ends of the tube?

Answer 8

They meet and react to form ammonium chloride

Question 9

Where does the ring form?

Answer 9

-Not exactly in the middle of the glass tube
-It forms nearest the end of the tube where the hydrochloric acid was

Question 10

Why does the ring not form exactly in the middle of the glass tube?

Answer 10

-It forms nearest the end of the tube where the hydrochloric acid was
-Because the particles of ammonia are smaller & lighter than the particles of hydrogen chloride -> so they diffuse through the air more quickly

Question 11

What colour is bromine gas?

Answer 11

Brown, strong smelling gas

Question 12

What can bromine gas be used for?

Answer 12

To demonstrate diffusion in gases

Question 13

Method: Bromine Gas & Air

Answer 13

1. Fill half a glass jar full of bromine gas & other half full of air -> separate gases with a glass plate
2. Remove the glass plate & brown bromine gas slowly diffuses

Question 14

How can you tell which gas diffuses quicker? NH3 or HCL?

Answer 14

-Ammonia diffuses more quickly, it will travel further than HCL in the same amount of time