States of Matter Chap. 13
State of matter in which particles are separated by large distances. I.Gases
A.Gas properties
I.Gases A.Gas properties 1.Gases have mass
I.Gases A.Gas properties 1.Gases have mass 2.Gases occupy space
I.Gases A.Gas properties 1.Gases have mass 2.Gases occupy space 3.Gases completely fill their containers
I.Gases A.Gas properties 1.Gases have mass 2.Gases occupy space 3.Gases completely fill their containers 4.Gases have low density
I.Gases A.Gas properties 5.Gases can be compressed & expanded
I.Gases A.Gas properties 5.Gases can be compressed & expanded 6.Gases exert pressure
I.Gases A.Gas properties 5.Gases can be compressed & expanded 6.Gases exert pressure 7.Gases diffuse & effuse
I.Gases B.The Kinetic Molecular Theory (KMT) An explanation of why gases behave the way they do.
I.Gases B.The Kinetic Molecular Theory (KMT) 1.Gases consist of tiny particles in constant motion
I.Gases B.The Kinetic Molecular Theory (KMT) 1.Gases consist of tiny particles in constant motion 2.Gas particles travel in straight line until they collide with other particles or the container
I.Gases B.The Kinetic Molecular Theory (KMT) 3.Gas particles are separated by relatively large spaces
I.Gases B.The Kinetic Molecular Theory (KMT) 3.Gas particles are separated by relatively large spaces 4.The kinetic energy of gas particles depends on the temperature KE = ½ mv 2
I.Gases C.Diffusion Spreading out of particles (high to low concentration)
I.Gases C.Diffusion 1.Diffusion depends on how fast particles travel.
I.Gases C.Diffusion 1.Diffusion depends on how fast particles travel. a.Cold particles travel _____ than warm particles.
I.Gases C.Diffusion 1.Diffusion depends on how fast particles travel. a.Cold particles travel slower than warm particles. b.Small particles travel _____ than small particles.
I.Gases C.Diffusion 1.Diffusion depends on how fast particles travel. a.Cold particles travel slower than warm particles. b.Small particles travel faster than small particles.
I.Gases C.Diffusion 1.Diffusion depends on how fast particles travel. 2.Graham found that the diffusion rate was inversely proportional to the square root of the molar mass.
Graham’s Law Rate A √ Rate B = Molar mass B Molar mass A
II. Measuring Gases A.Gas Pressure
II. Measuring Gases A.Gas Pressure 1.Pressure is force per area P = F/A
II. Measuring Gases A.Gas Pressure 1.Pressure is force per area 2.The atmosphere exerts pressure
II. Measuring Gases A.Gas Pressure 1.Pressure is force per area 2.The atmosphere exerts pressure 3.Pressure units
Equivalent Pressure units 1.00 atmosphere (atm) pascals (Pa) kilopascals (kPa) 760 __________ (mm Hg) 760 torricelli (torr) 14.7 pounds per square inch (___)
II. Measuring Gases A.Gas Pressure 1.Pressure is force per area 2.The atmosphere exerts pressure 3.Pressure units 4.Converting pressure
Self Check – Ex. 1 A container of gas has a pressure of 50 atm. What is this pressure in psi?
Self Check – Ex. 2 What is the pressure in pascals of a gas sample that is 140 kPa?
II. Measuring Gases B.Instruments
II. Measuring Gases B.Instruments 1.Barometer Measures atmospheric pressure.
II. Measuring Gases B.Instruments 1.Barometer Atmosphere ‘holds up’ a column of mercury a.Mercury Image: Dr. Leon L. Combs
II. Measuring Gases B.Instruments 1.Barometer a.Mercury b.Aneroid Name means ‘without liquid’ Image: Australian BOM
II. Measuring Gases B.Instruments 1.Barometer 2.Manometer Measures pressure of an enclosed gas 22 mm Hg CO 2
II. Measuring Gases B.Instruments 1.Barometer 2.Manometer 3.Example calculations
Self Check – Ex. 3 What is the pressure of the CO 2 gas pictured below? Atmospheric pressure is 755 mmHg. 22 mm Hg CO 2
Self Check – Ex. 4 What is the pressure of the helium gas pictured below? Atmospheric pressure is 1.1 atm. 65 mm Hg He
The End