Chapter 5 Gas- matter that has no definite shape or volume, takes both the shape and volume of its container Kinetic Theory of Gases -states that tiny particles of gases are in constant motion Basic Assumptions of Kinetic Theory: 1)no attractive or repulsive forces exist between gas particles -particles are very far apart from one another -empty space between particles explains gas compressibility

2)gas particles move in constant random motion 3)all collisions between gas particles are perfectly elastic -during collisions kinetic energy is transferred without loss from one particle to another -kinetic energy remains constant Variables Affecting Gases 1) gas pressure (P)- force exerted by a gas per unit surface area of an object, due to collisions of gas particles with an object barometer and manometer- instruments used to measure pressure

-Pressure can be measured in: -kilopascals (kPa) -millimeters of (mm Hg)  1 mm Hg = 1 torr -atmospheres (atm) -pounds per square inch (psi) **101.3 kPa = 760 mm Hg = 1 atm = 14.7 psi Convert: A) 3.45atm  mm Hg and kPa B) 893 mm Hg  kPa and atm

2)Volume (V) -amount of space an object occupies -expressed in Liters (L) 3)Temperature (T) -how hot or cold something is -must be expressed in K 4) Amount of Gas (n) -expressed in moles **Remember STP (standard temp and pressure) T= 273 K, 0°C P= kPa, 760 mm Hg, 1 atm