Gases 4

Is the glass half-full or half-empty? 5

6

Composition of Air 7 §05-01: Gases – SUBSTANCES THAT EXIST AS GASES

8 Noble Gases HONClBrIF CH 4 (methane) CO (carbon monoxide) NH 3 (ammonia) NO 2 (nitrogen dioxide) Common Gases

Diatomic Molecules: Elements that exist in pairs as gases at room temp. Br H Cl ON I F 7 – 6 = 1 = H H O N Cl Br I F

Some Gases of Interest & Importance Photosynthesis CO 2 +H 2 O  C 6 H 12 O 6 +O 2 Cellular Respiration C 6 H 12 O 6 + O 2  CO 2 +H 2 O

Some Gases of Interest & Importance

Pressure Definition:

Pressure Definition: Force / Area

Atmospheric Pressure The pressure at the ocean beach on a nice day is 1 atmosphere (1 atm)

Atmospheric Pressure How is it measured? 1 atm = 760 mm Hg torr = 760 torr Barometer

Pressure of a Gas Sample How is it measured? Manometer

Pressure How is it measured? Sphygmomanometer

18 1 atm = 760 mm Hg = 760 torr = 14.7 psi Units of Pressure used in Chemistry To compare the conditions of gases: Standard Temperature & Pressure (STP) Temperature = Pressure= 0 o C 1 atm

19 1 atm = 760 mm Hg = 760 torr = 14.7 psi Units of Pressure used in Chemistry 1 atm= 760 torr = 760 mm Hg = 14.7 psi (pounds per inch 2 ) = kPa (kiloPascal)

20 1 atm = 760 mm Hg = 760 torr = 14.7 psi Units of Pressure used in Chemistry The average atmospheric pressure in Denver, Colorado, is atm. Convert this pressure to: (a)mm Hg (b)torr (c)psi (d)kPa mm Hg torr psi psi