Diffusion Of Molecules Flashcards
(12 cards)
Diffusion
Particles moving from a high concentration to a low
Factors that affect the rate of diifusion
Concentration gradient- the bigger the gradient the bigger the rate
Shape and size of molecules- small molecules diffuse quicker than large
As well as long thin ones instead of fast and bulky
Temperature- higher the temp the more energy and faster they move increasing rate
Distance- the further they have to travel longer it takes
Quicker on short diffusion paths
Surface area- greater surface area the faster the rate of membrane
The diffusion of bromine in air
A gas jar of air us placed above a gas jar of bromine
The bromine starts to diffuse into the gas jair of air even though it is denser than air. After some time the bromine will spread evenly throughout the two gas jars
The diffusion of bromine in air explanation
Both bromine molecules and air molecules are constantly moving and colliding with walls. Results in v4omine moleculesnmoving into the upper gas jar and some air molecules moving into Lowe gas. Process continues until gully mixed and bromine moved from a high to low concentration
The diffusion of hydrogen chloride and ammonia gases
Two cotton wool soacked in concerted hydrochloric acid and soaked in concentrated ammonia solution then placed at ends or long tube clamped so it is horizontal
After few minutes a white ring of ammonium chloride starts to form at the end of tube which contains cotton wool soaked in hydrochloric acid
The diffusion of hydrogen chloride and ammonia gases explanation
Concentrated hydrochloric acid gives off hydrogenbchloride gas and the concentrated ammonia gives off ammonia gas. Both diffuse along the tube and when they meet they react to form ammonia chloride which is a white solid . Ammonia has smaller molecules and is less dense than hydrogen chloride. It diffused quicker so ammonia chloride is closer to hydrochloric end
Albert Einstein theory 1905
Came up with the theory that the pollen grains were moving because they were bombarded by the smaller water molecules. This was the first evidence to show that molecules in liquids and gases are constantly moving in random fashion
By observing tjis led to kinetic model of matter
Kinetic model of matter
All matter is made up of very small particles which are in constant motion
What happens when the particles in solids, liquids and gases are at any temp above zero
Will all exhibit some form of movement and at absolute zero all movement of particles stops
Absolute zero
Lowest possible temp which is -273 degrees celciud
What happens to particles when temp is increased
Particles gain more kinetic energy and vibrate more quickly
Dynamic equilibrium
When two processes take place at the same rate so there is no further change in concentration of the substances involved