diffusion

Question 1

define diffusion

Answer 1

diffusion is the net, passive movement of particles from an area of higher concentration to an area of lower concentration across a partially permeable membrane

Question 2

define equilibrium

Answer 2

when the concentration on both sides of the membrane are equal, meaning that the net movement of particles hasn’t entirely stopped but are just moving very briefly so diffusion is still continuing.

Question 3

define why particles move

Answer 3

particles move due to the kinetic energy they posses and energy can be increased by heat. the more kinetic energy a particle has, the more it’ll move.

Question 4

define solvent

Answer 4

allows a solute to dissolve in it

Question 5

define solute

Answer 5

a soluble substance that will dissolve into a solvent

Question 6

define solution

Answer 6

the mixture created when a solute is dissolved into a solvent

Question 7

describe the difference between a concentrated and dilute solution

Answer 7

a concentrated solution has more solvent that solute whereas a dilute solution has more solute than solvent

Question 8

describe the formula for calculating the concentration ( gdm⁻³ )

Answer 8

mass of solute ( g )
concentration ( gdm⁻³ ) = ————————–
volume of solvent ( dm⁻³ )

gdm⁻³ = g/dm⁻³

1L = 1 cubic decimetre
1cm³ = 1ml

Question 9

define the gradient

Answer 9

the difference of concentration in its values.
the larger the difference -> the faster it will diffuse
when reaching equilibrium the rate of diffusion will be slower

Question 10

define a concentration gradient

Answer 10

as particles diffuse from an area of higher concentration to an area of lower concentration, its called moving along a concentration gradient

Question 11

describe how temperature affects the rate of diffusion

Answer 11

heat from the rising temperature gives particles kinetic energy which speeds the rate of diffusion as the particles now move faster

Question 12

describe how surface area affects the rate of diffusion

Answer 12

a larger surface area results an increase of diffusion

Question 13

list three things that increase the rate of diffusion

Answer 13

-» concentration gradient
-» distance = shorter distance = efficient diffusion
-» surface area
-» temperature

Question 14

describe the formula to calculate surface area

Answer 14

surface area = width x length x number of faces

Question 15

define an exchange surface

Answer 15

areas that are specialised to maximise diffusion with minimal efforts

Question 16

define osmosis

Answer 16

the passive, net movement of water from a dilute solution to a concentrated solution through a partially permeable membrane.

Question 17

describe the golden rule for osmosis

Answer 17

-» describe what is moving
-» by what process
-» from where and why
-» across a partially permeable membrane
-» what is the effect of this?