12.1 Characteristics of Gases
I. Properties of Gases A.Fluid – they are able to flow Diffusion
B. Low density – large distance between gas particles
C. Highly compressible – a small amount of pressure move gas particles closer together Low pressure Larger volume High pressure Smaller volume
D. Completely fill a container I 2 (s) I 2 (g)
II. Measuring Gases Values of the FOUR gas variables - Amount of Gas (n): n = mass/molar mass Volume (V): 1 L = 1000 cm 3 Temperature (T): Measured in Kelvins Pressure (P): (see conversion sheet)
Scientists have specified a set of standard conditions called: standard temperature and pressure (STP) = 0 o C and 1.00 atm
Converting Temperature 15 o C = _____ K 312 K = _____ o C 15 o C K ‒ o C = _____ o F (1.8)(25 o C) o F = _____ o C (6.5 o F ‒ 32) ÷ 1.8 ‒
Converting Pressure Units The air pressure in a cabin of an airplane is 8.3 psi. What is this pressure in torr units? 430 torr 8.3 psi 1 atm psi 1 atm 760 torr