CHAPTER 6:PROPERTIES OF MATTER
5.1 STATE OF MATTER
5.3 PROPERTIES OF GASES AND GAS LAWS
IN THE INCREASING OF ENERGY, SOLIDS>LIQUIDS>GASES>PLASMAS
SOLID
FIXED VOLUME AND SHAPE
LIQUID
FIXED VOLUME BUT TAKE THE SHAPE OF THE CONTAINER
GAS
VIBRATE BUT STAY IN FIXED POSITION
MOVE RELATIVE TO ONE ANOTHER
NO FIXED VOLUME OR SHAPE
FREE TO MOVE INDEPENDENT
PLASMA
GAS THAT HAS IONISED DUE TO VERY HIGH TEMPERATURE
ELECTRICALLY CHARGED AND IS AFFECTED BY MAGNETIC
BOYLE'S LAW
VOLUME OF A GIVEN MASS OF A GAS IS INVERSELY PROPOTIONAL TO PRESURE AT CONSTANT TEMPERATURE
P1V1=P2V2
CHARLES LAW
VOLUME OF A GIVEN MASS OF A GAS IS PROPOTIOONAL TO ABSOLUTE TEMPERATURE AT CONSTANT PRESSURE
V1/T1=V2/T2
AVOGADRO'S LAW
VOLUMES OF GASES ARE PROPORTIONAL TO THE NUMBER OF ATOMS OR MOLECULES
IDEAL GAS LAW
COMBINATION OF BOYLE;S LAW,CHARLES LAW AND AVOGADRO'S LAW
PV=nRT
GAY-LUSSAC'S LAW
PRESSURE OF A GIVEN MASS OF A GAS IS PROPORTIONAL TO ABSOLUTE TEMPERATURE AT CONSTANT VOLUME
P1/T1=P2/T2
DALTON'S LAW OF PARTIAL PRESSURE
USED FOR DETERMINING THE ACTUAL PRESSURE OF A GAS COLLECTED BY THE WATER DISPLACEMENT METHOD
P(H20 VAPOR)+P(DRY GAS)=P(TOTAL)
P(TOT)=P(A)+P(B)+P(C)
GRAHAM'S LAW OF EFFUSION
DIFFUSION:RATE AT WHICH TWO GASES MIX
EFFUSION:RATE AT WHICH A GAS MOVES THROUGH A SMALL HOLE
THE RATE OF EFFUSION OF A GAS IS INVERSELY PROPORTIONAL TO THE SQUARE ROOT OF ITS DENSITY
KINETIC THEORY OF GASES
5.3 PROPERTIES OF LIQUID
VISCOSITY
SURFACE TRNSION
VAPOR PRESSURE
COLLIGATIVE PROPERTIES
VAPOR PRESSURE LOWERING
THE VAPOR PRESSURE OF A SOLUTION CONTAINING NONVOLATILE SOLUTE IS LOWER THAN THE PURE SOLVENT
Psolution = Xsolute Po
where,
Psolution is the vapor pressure difference
Xsolute is the mole fraction of the solute
Po is the vapor pressure of the pure solvent :
BOILING POINT ELEVATION
THE BOILING POINT OF A SOLUTION CONTAINING NONVOLATILE IS GREATER THAN THE BOILING POINT OF THE PURE SOLVENT
Tb = Kb x m
WHERE
Tb = boiling pt of solution - boiling pt of solvent
Kb is the boiling pt elevation constant
m is the molality of the solution
FREEZING POINT DEPRESSION
THE FREEZING POINT OF A SOLUTION CONTAINING NONVOLATILE IS LOWER THAN THE FREEZING POINT OF THE PURE SOLVENT
Tf = - Kf x m
where,
Tf = freezing pt of solution - freezing pt of solvent
Kf is the freezing pt depression constant
m is the molality of the solution
OSMOTIC PRESSURE
THE OSMOTIC PRESSURE IS THE BACK PRESSURE NEEDED TO PREVENT OSMOSIS.
OSMOSIS REFER TO THE FLOW OF SOLVENT MOLECULES PAST A SEMI PERMEABLE MEMBRANE.
A SEMIPERMEABLE MEMBRANE ALLOWS THE PASSAGE OF SOLVENT MOLECULES BUT BLOCKS THE PASSAGE OF SOLUTE MOLECULES
p = M R T
where,
𝜋"=osmotic pressure "("atm")
𝑀" = molar concentration of solution "("mol/L")
𝑅" = 0.0821" "L atm" /"mol K"
𝑇" = absolute temperature "(K)
5.4 PROPERTIES OF SOLID
CRYSTALLINE SOLIDS
UNIT CELLS,CRYSTAL LATTICES AND CRYSTAL SYSTEM
1.THEY HAVE SHARP MELTING POINT
2.ATOMS,MOLECULES OR IONS ARE ARRANGED IN A REGULAR PATTERN
3.THEY EXHIBIT ANISOTROPIC PROPERTIES
IONIC CRYSTALS
CONSIST OF POSITIVE AND NEGATIVE IONS ALTERNATELY ARRANGED
HAVE HIGH MELTING POINTS,TEND TO BE HARD OR BRITTLE
CONDUCT ELECTRICITY IN THE MOLTEN OR SOLUBLE STATE
MOLECULAR CRYSTALS
CONSIST OF UNCHARGED ATOMS/MOLECULES
HAVE LOW MELTING POINT AND TEND TO BE SOFT
NON CONDUCTORS
COVALENT CRYSTALS
A NETWORK OF COVALENTLY BONDED ATOMS FORMING A GIGANTIC MOLECULE
HAVE HIGH MELTING POINTS AND TEND TO BE HARD
NON CONDUCTORS
METALLIC CRYSTALS
CONSIST OF POSITIVE METAL IONS
MELTING POINTS AND HARDNESS DEPEND ON THE NUCLEAR CHARGE AND ELECTRONS
CONDUCTORS
UNIT CELLS
CRYSTAL LATTICES
SMALLEST BASIC UNIT OF A CRYSTAL
A CRYSTAL LATTICE IS THE REPEATING PATTERN OF PARTICLES IN A CRYSTALLINE SOLID
CRSTAL SYSTEM
METHOD OF CLASSIFYING CRYSTALLINE SUBSTANCES ON THE BASIS OF THEIR UNIT CELLS
AMORPHOUS SOLID
AMORPHOUS SOLID
1.PARTICLES HAVE NO REGULAR PATTERN OF ARRANGEMENT
2.MELT OVER A RANGE OF TEMPERATURES
THE CUBIC SYSTEM
SIMPLE CUBIC SYSTEM(HAVE A LATTICE POINT AT EACH CORNER OF THE UNIT CELL)
BODY-CENTERED CUBIC LATTICE(ADD A LATTICE POINT IN THE CENTRE AND EACH CORNER OF THE UNIT CELL)
FACE-CENTERED CUBIC LATTICE(HAS A LATTICE POIN AT EACH CORNER AND AN ADDITIONAL ATOM AT EACH OF ITS SIX FACES OF THE UNIT CELL)
NUMBER OF UNITS IN A UNIT SELL
THE NUMBER OF UNITS(ATOMS,IONS OR MOLECULES) IN A UNIT CELL CAN BE CALCULATED BY APPLYING THE FOLLOWING RULES
CLOSE PACKING AND COORDINATION NUMBER
A SOLID CRYSTAL IS BUILT UP BY PLACING CLOSED PACKED LAYEERS OF SPHERES
A COORDINATION NUMBER IS DEFINED AS THE NUMBER OF SPHERICAL UNITS THAT SURROUND A GIVEN UNIT,
EFFICIENT PACKING OF ATOMS IN SOLIDS ARE KNOWN AS CLOSE-PACKING
MEASURE OF THE RESISTANCE TO FLOW
LIQUID TEND TO BE MORE VICOUS AS THE SIZE OF MOLECULES BECOME LARGER,AS THE AMOUNT OF INTERMOLECULAR BONDING INCREASES AND THE TEMPERATURE DECREASES
FORCE THAT CONTROL THE SHAPE OF THE LIQUID
PRESSURE OF THE VAPOR ABOVE THE LIQUID AT A GIVEN TEMPERATURE
THE GAS PRESSURE UNDER THIS EQUILIBRIUM(THE RATE AT WHICH MOLECULES EVAPORATE IS EQUAL TO THE RATE AT WHICH MOLECULES RETURN YO THE LIQUID)IS CALLED VAPOR PRESSURE
AT THE SURFACE,THE FORCE OF ATTRACTION PULLS THE MOLECULES INTO THE LIQUID