states of matter Flashcards
there are 3 states of matter. what are they?
- solid
- liquid
- gaseous
what are the particulate theory of matter
- all matter is composed of particles
- the particles are in constant motion and temperature affects their speed of motion
- the particles have empty spaces between them
- the particles have forces of attraction between them
what is diffusion
diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration, until the particles are evenly distributed
what are some examples of diffusion
cotton wool and hcl
explain this lab
pieces of wool are soaked in ammonia solution and conc hcl is placed simultaneously on opposite ends of the glass tube. a white ring of ammonium chloride forms inside.
chemistry behind ammonia and hcl
ammonia particles diffuse faster than hydrogen chloride particles, so there they collide and form at the side of hcl ( where it was slower)
another example of diffusion
potassium manganate crystals
what happens here when kmno crystals are placed in water?
when kmno crystals are placed in water, it dissolves to produce a uniformly purple solution. the particles that makes up the crytals diffuse through the spaces within the water until they are evenly distributed.
what is osmosis
osmosis is the movement if water molecules through a differentially permeable membrane from a solution containing a lot of water molecules.
what are some examples of osmosis
when a strip of paw paw was placed in water, water molecules move into the cells by osmosis. each cell swells slightly therefore the strip increases in length and becomes rigid.
another explanation follows when pawpaw strips are placed in water
when the strip is placed in a conc solution of NaCl solution, water molecules move out of the cells by osmosis. each cells shrink therefore decreases in length and becomes softer.
uses of osmosis
- to control garden pests
2. to preserve food
explain the first use of osmosis- to control garden pests
pests that have permeable skin and is always moist, salt can dissolve in the moisture around their bodies forming a conc solution. water inside their bodies move out by osmosis and into the solution they then die from dehydration
explain the second use of osmosis- to preserve food
salt and sugar are used to preserve foods eg meat, fish and fruits. they draw water out of the cells of the food by osmosis. this prevents the food from decaying bc there is no water available in the cells for chemical reactions to occur
another explanation
they draw water out of microorganisms by osmosis. this prevents the food from decaying bc it inhibits the growth of microorganisms.
types of particles that make up matter are
- atoms
- molecules
- ions
explain the properties of solid, liquid and gas in their states
solid- fixed shape and volume, high density, difficult to compress, packed closely-usualy tgt, strong force of attraction, posses small amt of kinetic energy, vibrate in their fixed positions
describe liquid in its states
takes shape of container, fixed volume, denisty is lower than solids, can be compressed by applying pressure, have small spaces btween them and are randomly arranged, weaker than those between the particles in solid, posses more kinetic energy, move slowly pass eachother,
explain gas
takes the shape of the entire container, variable density- expands to fill container, low density, very easy to compress, have large spaces between them and are randomly arranged, very weak force of attraction, posses large amt of kinetic energy, ,move around freely and rapidly.
changing state of solid
when it is heated, it changes from liquid to gas. this happens bc the particle gain kinetic energy, move increasingly faster and further apart, and the forces of attraction becomes weaker.
what happens to gas
when a gas is cooled, it changes from liquid to solid. this occurs bc the particles lose energy, move more slowly and closer tgt, and the forces of attraction becomes stronger.
what is a heating curve
a heating curve is drawn when the temperature of a solid is measure at intervals as it is heated and changes states to a liquid and then to a gas.
temperature is plotted against time
what is a cooling curve
this is when the temp of a gas is measured at intervals when it is cooled and changes state to a liquid. the temp is plotted against time
what is the melting point
this is the constant temperature at which a solid changes into a liquid
what is the boiling point
this is the constant temp at which a liquid changes into gas
what is the freezing point
this is the constant temperature at which a liquid changes into a solid
