Diffusion

Question 1

Particles in a solid

Answer 1

• closely packed
• very little movement
• structured order

Question 2

Particles in a liquid

Answer 2

• little space between atoms
• flow over each other
• random order

Question 3

Particles in a gas

Answer 3

• lots of space between

- atoms move quickly/randomly

Question 4

As volume increases, _______ _______ ?

Answer 4

as volume increases, pressure decreases.

Question 5

As volume decreases, ______ ______?

Answer 5

As volume decreases, pressure increases

Question 6

why does the pressure change due to the volume?

Answer 6

Because the atoms become a lot more tightly packed in a small volume, this allows the atoms to collide a lot more frequently. If there was a larger volume there would be more space between the atoms so they would not collide as frequently. (assuming the number of particles and temperature remains constant )

Question 7

what is diffusion ?

Answer 7

diffusion is the movement of particles from a high concentration to a low concentration.

Question 8

what is a high concentration?

Answer 8

when there is a lot of particular atoms in one particular space. (small volume) the particles are close together.

Question 9

What is a low concentration?

Answer 9

when there is not a lot of one type of particle in a small area. the particles are more spread out.

Question 10

What affects diffusion ?

Answer 10

• temperature
• concentration
• distance

Question 11

how do you work out atomic weight ?

Answer 11

add up the atomic mass of each element

Question 12

atomic mass of HCl

h = 1 cl =35.5

Answer 12

h = 1 cl =35.5

= 36.5

Question 13

in 18__ R____ B____ looked at ____ ____ in _____ through a ____, the ___ ___ j____ about, he did not know why this was happening and named it B_____ _____.

Answer 13

In 1827 Robert BRown looked at pollen grains in water through a microscope, the pollen grains jiggled about, he did not know why this was happening and named it Brownian Motion

Question 14

Einstein realised that the pollen grains seen in Brownian motion was due to ….

Answer 14

the molecules of the water hitting the pollen - the pollen grains were visible but the water molecules were not.

Question 15

What is Brownian motion ?

Answer 15

the random motion of particals

Question 16

when was Brownian motion first observed (and by who )

Answer 16

Robert Brown, 1827

Question 17

Smoke particles look like they are moving around randomly because …

Answer 17

They are colliding with the particles in the air which are not visible and the smoke particles are.

Question 18

How does the size ratio of particles affect the the movement of particles?

Answer 18

the bigger the particles the less they are able to move as they collide alot more frequently. They would also take up alot more space meaning there is less space to move around.

Question 19

How does the amount of energy affect the movement of particles ?

Answer 19

the particles are able to move a lot more if they have more energy, this causes them to collide alot more frequently with other particles.

Question 20

How does the mass ratio affect the movement of the particles?

Answer 20

the heavier particles are able more to the lighter particles a lot faster when colliding.

Question 21

What is a dynamic equilibrium ?

Answer 21

It is where a reaction is reversible. Each way of the reaction, forwards and backwards happen at equal rates.

Question 22

What is dynamic equilibrium in the process of diffusion

Answer 22

it means a balanced solution has been reached (the particles are evenly spread out).

Question 23

Precision

Answer 23

• consistency (any value )

Question 24

Accuracy

Answer 24

• consistency (to the true value )

Question 25

why does distance affect the rate of diffusion ?

Answer 25

• smaller distances causes faster diffusion rates.

- larger distances, slower diffusion rates