SCIENCE FOURTH

• GAS IS A STATE OF MATTER
• GAS PHYSICAL CHARACTERISTICS ARE NOT READILY SEEN
• GAS WHEN WE VARY THEIR TEMPERATURE AND PRESSURE, THEIR BEHAVIOR CAN EASILY BE PREDICTED
• GAS HAS NO DEFINITE SHAPE AND VOLUME
• GASES VOLUME IS THE VOLUME OF THEIR CONTAINER BECAUSE THEY OCCUPY ALL SPACES AVAILABLE IN THEIR CONTAINER
• GASES ARE COMPRESSIBLE WHEN PRESSURE IS EXERTED AND THEY ALSO EXERT PRESSURE
• GASES EXPAND WHEN HEATED AND CONTRACT WHEN COOLED
• GAS INTERMOLECULAR FORCE OF ATTRACTION BETWEEN THEIR PARTICLES IS NEGLIGIBLE THUS THEY DIFFUSE EASILY
• THE COMMON UNITS OF VOLUME USED IN GAS MEASUREMENTS ARE LITER (L), MILILITER (ML), CUBIC METER (M3) AND CUBIC CENTIMETER (CM3)
• THE PRESSURE OF A GAS IS THE FORCE EXERTED BY THE GAS MOLECULES ON THE WALLS OF ITS CONTAINER DIVIDED BY THE SURFACE AREA OF THE CONTAINER
• EARTH ATMOSPHERE EXERTS PRESSURE ON US AT 1.013X10^5 N/M^2 OR 1ATM (ATMOSPHERE)
• ATMOSPHERIC PRESSURE DECREASES AS ALTITUDE INCREASES
• COMMON UNITS OF PRESSURE AND THEIR EQUIVALENT ARE ?

  1ATM = 1.013X10^5 N/M^2 = 1.013X10^5 PA

  1ATM = 760 TORR = 760 MMHG

  1ATM = 14.696PSI
• THE TEMPERATURE OF A GAS IS THE AVERAGE KINETIC ENERGY OF THE PARTICLES OF GAS
• TEMPERATURE IS USUALLY DETERMINED USING A THERMOMETER
• TEMPERATURE IS USUALLY EXPRESSED IN

  DEGREE CELCIUS

  DEGREE FARENHEIT

  KELVIN
• ONLY KELVIN IS USED IN COMPUTATIONS INVOLVING TEMPERATURE OF GAS
• C = (F-32)/1.8
• F = 1.8C+32
• K= C+273
• STANDARD CONDITION FOR A GAS IS ALSO KNOWN AS STP OR THE STANDARD TEMPERATURE AND PRESSURE
• STANDARD TEMPERATURE IS THE MELTING OF AN ICE WHICH IS 0 DEGREE CELCIUS OR 273K
• STANDARD PRESSURE IS THE AVERAGE PRESSURE OF THE ATMOSPHERE AT SEA LEVEL WHICH IS EQUAL TO 1ATM
• ONE MOLE OF A GAS OCCUPIES A VOLUME OF 22.4L
• FORMULA OF BOYLES LAW

  V1P1=V2P2

  WHERE AS 1 IS INITIAL AND 2 IS FINAL
• THE RELATIONSHIP BETWEEN THE VOLUME AND PRESSURE OF GASES AT CONSTANT TEMPERATURE WAS FIRST STATED BY ROBERT BOYLE DURING THE 16TH CENTURY
• ROBERT BOYLE CONCLUDED THAT THE VOLUME OF A FIXED AMOUNT OF GAS IS INVERSELY PROPORTIONAL TO ITS PRESSURE AT CONSTANT TEMPERATURE
• ROBERT BOYLE FOUND OUT THAT AS THE PRESSURE IS INCREASED THE VOLUME DECREASES
• GAS PARTICLES HAVE A VERY WEAK INTERMOLECULAR FORCE OF ATTRACTION HENCE THEY MOVE AS FAR AS POSSIBLE FROM EACH OTHER
• AT CONSTANT TEMPERATURE THE VOLUME OCCUPIED BY A FIXED AMOUNT OF GAS IS DIRECTLY PROPORTIONAL TO THE RECIPROCAL OF PRESSURE
• THE VOLUME-TEMPERATURE RELATIONSHIP IN GASES WAS DETERMINED BY AND NAMED AFTER JACQUES CHARLES
• FOUR PROPERTIES OF GAS

  PRESSURE (P)

  VOLUME (V)

  TEMPERATURE (T)

  AMOUNT (N)
• PRESSURE - FORCE ACTING ON A SPECIFIC AREA
• VOLUME IS THE THREE DIMENSIONAL SPACE OCCUPIED BY GAS
• TEMPERATURE MEASURE OF THE WARMTH OR COLDNESS OF A BODY
• TEMPERATURE MEASURE OF THE AVERAGE KINETIC ENERGY OF THE PARTICLES IN AN OBJECT
• QUANTITY IS MEASURE IN MOLES
• 1 MOLES IS EQUAL TO 6.022X10^23 UNITS OF A SUBSTANCE
• SAME MASS DIFFERENT AMOUNTS OF SUBSTANCE
• DIFFERENT MASS SAME AMOUNT OF SUBSTANCE