unit 1 particles and mixtures
what are the 3 states of matter
solid ,liquid,gas
which state you get depends on what?
how strong forces of attraction are between particles of material
how strong forces are depends on what 3 things
material ,tempertuare and preassure
describe the forces of attraction in a solid?
strong forces of attraction between particles,holds them close together in fixed positions to form very regular lattice arrangement
describe the particles in a solid?
particles dont move from their positions .hotter solid is more they vibrate
describe the forces of attraction in a liquid?
weak forces of attraction between particles.randomly arranged +free to move past eachother tend to stick closely together
describe shape of liquid?
definete volume but dont keep definite shape will flow to bottom of container
describe particles in a liquid?
particles constantly moving with random motion hotter liquid gets faster they move causes liquid to expand slightly when heated
describe forces of attraction in a gas?
forces of attraction very weak free to move and far apart particles in gas travel straight
describe shape of gas?
dont keep shape or volume will always fill any container
describe the particles in a gas?
particles move constantly with random motion. hotter gas gets faster they move gases expand when heated or preasure increases
what is diffusion?
movement of particles through liquid or gas.diffusion is gradual movement of particles from places where there are lots of them to places where there are fewer of them
explain experiment of potasium magnate(vii) and water
a beaker of water and place potasium magnate(vii) at bottom purple slowly spreads out to fill beaker particles of potasium magnate(vii) diffusing out among particles of water .random motion liquid causes purple to evenly spread through water .potasium magnate(vii) can be diluted by adding water . add more water to purple solution potasium magnate(vii) particles spread even further apart solution less purple shows dilution
explain experiment anmonia and hydrogen chloride
aqueous ammonia(nh3) gives off amonia gas hcl gives of hydrogen chloride gas nh3 gas diffuses from 1 end of tube and hcl diffuses from other when they meet react to form ammonia chloride .ring forms at nearest end of tube where hcl particles of ammonia smaller + lighter than hydrogen chloride particles diffuse through air quickly
describe experiment bromine gas and air
bromine gas is brown has strong smelling gas 1- fill half a gas jsr full of bromine has and other half with air seperate gasses with glass plate.when you remove glass plate bromine gass slowly diffuses through air random motion of particles means bromine will eventually diffuse through air
what is a solution
is a mixture if solvent+solute that does not seperate out.when you add solid(solute) to liquid (solvent) binds holding solute molecules together sometimes break + molecules the mix with molecules in liquid forming a solution called dissolving
what is a solute?
is the substance being dissolved
what is a solvent?
is the liquid its dissolving into
what is a saturated solution?
a solution where maximum amount of solute has been dissolved. no more solute will dissolve in solution.
what is solubility?
how much solute will dissolve in a solvent ability of substance to dissolve known as solubility .solubity meassured in grams or solute per 100 g of solvent
solubility of ammonia chloride affected by temp
make a saturated solution by adding excess ammonia chloride to 10cm3 of water in boiling tube it will become excess when sinker to bottom give solution good stir+ place boiling tube in water bath set to 25 degress after 5 mins check all excess solid sunk to bottom of tube use themomter check solution reaches 25 degrees. weigh empty evaporating basin pour some solution in basin .reweigh basin+contents gently heat using bunsen burner all water evaportated left with pure ammonia chloride
how do u measure solubility
solubility(g oer 100g solution)=mass of solid(g) / mass of water removed (g) x 100
what is an atom
made up of 3 subatomic particles protons,neutrons and electrons
describe a proton
heavy and positvely charged . relative mass 1 relative charge +1
describe a neutron
heavy and neutrol. relative mass 1 relative charge 0
describe a electron
hardly any mass negative charged 0.0005 relative mass relative cherge -1
what is a nucleus
in middle of atom contains protons+ neutrons positvely charged because protons whole mass of atom concentrated in nucleus
what is an electron
moves atound nucleus in energy levels called shells negatively charged tiny oribital cover lots of space+ determines size of atoms no mass electrons= protons netural atoms no charge charge electrons= charge protons in neutrol atom .if some electrons added or removed atome becomes charged than a ion
what is a atomic number
tells you how many protons of atoms of same element all have same number of protons atoms of different elements have different number of protons
what is mass number
total of protons+ neutrons in atom neutrons=atomic number-mass number
what is molecules
group of atoms atoms can join to form molecules some molecules made from 1 element (H2,N2) others made more than 1 (h2o,CO2)
what is an isiotope?
are different atomic forms of same element which have same n.o protons but different n.o neutrons isotopes have same proton number but different mass number if different proton number different elements
what is relative atomic mass
Ar how heavy different atoms are compared with mass
what is relative abundance
how much there is of each isotope compared to total amount of element in world
elements
consists of 1 type of atom e.g coller and aluminium
diatomic molecule
made with 2 atoms
compounds
chemically bonded compound made up of 2 or more different elements which are chemically bonded together e.g carbon dioxide compound formed from a chemical reaction
what is a mixture
easiliy seperated no chemical bond between different parts of mixture can be seperated out by physical methods such as distilstion .
filtration
used to seperate insoluble solid from liquid.if product of reaction is insoluble solid, filtration used to seperate out from liquid reaction mixture used in purification .filter paper in funnel pour mixture into liquid mixture runs through leaving solid residue
crystalisation
seperates soluble solid from solution pour solution into evaporating dish+ gently heat solution. some water will evaporate+ solution will get more concentrated.once some water evaportard or see crystals form remove dish from heat+ leave solution to heat .salt should start to form crystals befome insoluble in cold highly concentrated solution filter crystals out of solution leave in warm place to dry
seperation of rock salt
filtration+ crystalisation seperate rock salt . rock salt mixture of rock+sand salt + sand both compounds salt dissolves in water sand doesnt. 1- grinding gring rock pestle+mortar 2-dissolving dissilve in besker+stir 3- filtering filter through filter paper + funnel 4-crystalisation evaporate in evaporating dish sand doesnt dissokve ( insoluble ) stays in big grains solution goes through water evaporated salt forms as crystals in evaporating dish
chromotography
1) draw line bottom of sheet use pencil insoluble 2)add spots of different inks 3) roll up paper put in beaker of water(solvent) 4) place lid on top of container stop water evaporating 5) solvent seeps ul ester carry inks with it6) solvent bearl dried paper out of beaker dry end result pattern of spots called chromotogram
Rf value
ratio befween distance travelled by dissolved substance (solute)+ distance travelled by solvent Rf-B/A
simple distalation
seperating liquid from solution solution heated part of solution which has lowest boiling point evaporates vapour condenses+collects rest of solution left behind in flask can only use simple distalation to seperate things with different boiling points
fractional distalation
seperate mixture of liquids 1- put mixture in flask+ stick franctioning columb on top heat it 2- different liquids different boiling points will evaporate at different temps 3) liquid with lowest boiling point evaporates first when temp on themometer matches boiling point of liquid it will teach top 4- liquid with higher boiling points might also evaporate column cooler towards top only get part way before condensing and turning back towards flask when liquid has collected raise temp until next one reaches top