Page 1 :
STATES OF MATTER, GASEOUS STATE, , , , , , Gaseous State:, , Gaseous state is the simplest state of matter, where the particles are free to move rapidly in all, Jections gases are characterized by low density, high compressibility high expandability. Gases, exert uniform pressure on the walls of the container. They diffuse rapidly and intermix to form, homogeneous mixtures. The characteristics of gases are described fully in terms of four parameters., , (a) the volume, V, of the gas, , (b) its pressure, Ps, , (c) its temperature, i;, , (d) the amount of the gas (i.e, mass or number of moles), , (a) Volume: Volume is expressed is litre, mililitre, cubic centimeter (cm?) or (m’), 1 L= 1000 mL; 1 mL = 10° L, , 1L= 1 dm’; 1 dm? = 10° cm®, , 1 m= 10° dm? = 10° om? = 10° mL = 10° L., , 7,, , (b) Pressure: The force exacted by the gas per unit area of the walls of the container is known as, pressure. It is measured in atm. of, , 1 atm = 76 cm of mercury = 760 mm of mercury = Tobitotr ”, , S.I unit of pressure is pascal (Pa) Ors, , 1 atm = 101.325x10° Nm? = 101.325 kPa. »,, , , , (c) Temperature: S.I unit of temperatfire is Kelvin, K=°C +273 ), , (d) Mass of the gas is expressed in gm or kg., No. of moles of the gas (n) = Mass in gms (m) / Molar mass (M)