Chapter 17 (2) Kinetic Theory of Gases

Slides:

Advertisements

Similar presentations

KMT, Graham’s Law & Real Gases

Advertisements

Kinetic Theory of Gases I

The Kinetic Theory of Gases

PV = nRT Ideal Gas Law P = pressure in atm V = volume in liters

GASES Question 1: 1994 B Free Response

Gases and the Kinetic Molecular Theory. Speeds of gas molecules. For a single molecule. Kinetic energy is: KE = ½ mv 2 m = mass; v = velocity For a collection.

Gases and the Kinetic Molecular Theory. Speeds of gas molecules. For a single molecule. Kinetic energy is: KE = ½ mv 2 m = mass; v = velocity For a collection.

Kinetic Theory of Gases Physics 202 Professor Lee Carkner Lecture 15.

Gases and the Kinetic Molecular Theory. Speeds of gas molecules. For a single molecule. Kinetic energy is: KE = ½ mv 2 m = mass; v = velocity For a collection.

TOPICS 1.Intermolecular Forces 2.Properties of Gases 3.Pressure 4.Gas Laws – Boyle, Charles, Lussac 5.Ideal Gas Law 6.Gas Stoichiometry 7.Partial Pressure.

The Kinetic Theory of Gases

Kinetic Theory of Gases Physics 202 Professor Lee Carkner Lecture 13.

Copyright © 2009 Pearson Education, Inc. Chapter 18 Kinetic Theory of Gases.

4.3.4 Ideal Gases.

Properties of Gases Important properties of a Gas Quantity n = moles

Gas Laws. Gas Pressure ____________ is defined as force per unit area. Gas particles exert pressure when they ____________ with the walls of their container.

Avogadro’s Principle Gas particles = big, little, heavy, light Doesn’t matter = so far apart Therefore, a 1000 krypton (big) atoms occupy the same space.

Real gas 1.molecules not always in motion (condense phase can be formed) 2.molecular size is non-negligible (there is molecular repulsion) 3.Molecules.

CHAPTER 15 : KINETIC THEORY OF GASSES

5.3b Thermal Physics Gases Breithaupt pages 210 to 218 January 31 st 2011.

Gases Courtesy of nearingzero.net.

C H A P T E R 14 The Ideal Gas Law and Kinetic Theory

Ideal Gas Law PV=nRT Kinetic Molecular Theory 1. Gases have low density 2. Gases have elastic collisions 3. Gases have continuous random motion. 4. Gases.

Lesson 4: Ideal Gas Law This lesson combines all the properties of gases into a single equation.

The Chapter 14 Behavior of Gases.

Kinetic Molecular Theory 1. Gases consist of large numbers of molecules in continuous, random motion. 2. The volume of the molecules of a gas is negligible.

Chapter 5: Gases 5.1 Pressure. Gaseous State of Matter  has no distinct or __________ so fills any container  is easily compressed  completely with.

Gases Chang Chapter 5. Chapter 5 Outline Gas Characteristics Pressure The Gas Laws Density and Molar Mass of a Gas Dalton’s Law of Partial Pressure Kinetic.

Unit IX: Gases… Part II Chapter 11… think we can cover gases in one day? Obviously not… since this is day 2… but let’s plug away at it!

Chapter 10: Gases.

Kinetic Molecular Theory and Real Gases ROOT MEAN SQUARED, EFFUSION, REAL GASES.

Kinetic Molecular Theory. The model of Gases Most of our knowledge of gases comes from a model of how gases work. The model of a real gas would look something.

Kinetic Molecular Theory (KMT) 1.Gases consist of large numbers of molecules that are in continuous, random motion. 2.The volume of all of the gas molecules.

Gas Laws AP Physics B. The Periodic Table All of the elements on the periodic table are referred to in terms of their atomic mass. The symbol u is denoted.

1 Graham’s Law Gases expand to occupy the volume that is available to it. This is Diffusion – movement from _____ concentration to _______ concentration.

Chapter 14-3 I. Avogadro’s Principle A. Equal volumes of gases at same T and P contain equal #’s of molecules B. H 2 + Cl 2 → 2HCl 1 vol. 1 vol. 2 vol.

Root Mean Square Velocity (urms)

Chapter 14-3 I. Avogadro’s Principle A. Equal volumes of gases at same T and P contain equal #’s of molecules B. H 2 + Cl 2 → 2HCl 1 vol. 1 vol. 2 vol.

The Kinetic Theory of Gases Temperature as a measure of average kinetic energy of the particles.

Chapter 101 Gases. 2 Homework: 10.12, 10.28, 10.42, 10.48, 10.54, 10.66,

Ideal gases and molar volume

Ideal Gas Law Chapter Ideal Gas Law The ideal gas law combines: –pressure –temperature –volume –# of particles (amount)

Ideal Gases. Ideal Gas vs. Real Gas Gases are “most ideal”… at low P & high T in nonpolar atoms/molecules Gases are “real”… Under low T & high P when.

Preludes to the Ideal Gas Equation Pressure (P) inversely proportional with Volume (V) at constant Temperature Boyle’s law.

Thermal Physics 3.2 Modelling a gas. Understanding  Pressure  Equation of state for an ideal gas  Kinetic model of an ideal gas  Mole, molar mass,

Thermodynamics Kinetic Theory of Gases (Section 10.6)

Unit 1 Gases. Ideal Gases Objectives 1. Compute the value of an unknown using the ideal gas law. 2. Compare and contrast real and ideal gases.

Gases Online Lecture Part 3. Kinetic Molecular Theory Four Postulates 1.The particles are ________ in comparison to the space they occupy that the _______of.

Relate number of particles and volume using Avogadro’s principle. mole: an SI base unit used to measure the amount of a substance; the amount of a pure.

GASES. Gases  The physical state of gases is defined by several physical properties  Volume  Temperature  Amount (commonly expressed as number of.

UNIT 6: CHEMICAL QUANTITIES Chapter 10: Mole and Volume Relationships.

Thermal Physics 3.2 Modelling a gas. Understanding  Pressure  Equation of state for an ideal gas  Kinetic model of an ideal gas  Mole, molar mass,

Chemistry – Chapter 14.  Kinetic Theory assumes the following concepts:  Gas particles don’t attract or repel each other  Gas particles are much smaller.

The Ideal Gas Law. Remember… and In an Ideal Gas, Therefore, in an Ideal Gas, Combined Gas LawAvogadro.

Prentice Hall © 2003Chapter 10 Chapter 10 Gases CHEMISTRY The Central Science 9th Edition.

The Ideal Gas Law Ideal Gas  Follows all gas laws under all conditions of temperature and pressure.  Follows all conditions of the Kinetic Molecular.

The Kinetic Theory of Gases

To understand the Ideal Gas Law and use it in calculations

Properties of Gases Kinetic Molecular Model Speed of gas

PV = nRT Ideal Gas Law Ideal Gases Avogadro’s Principle Ideal Gas Law

The Kinetic Theory of Gases

Ideal Gases Kinetic Theory of Gases

Objectives To understand the relationship between laws and models (theories) To understand the postulates of the kinetic molecular theory To understand.

To understand the Ideal Gas Law and use it in calculations

States of Matter Lesson 4.5

Presentation transcript:

Chapter 17 (2) Kinetic Theory of Gases

Ideal Gas Law The law R = 0.08206 L.atm/(mol.K) is approximately true for real gases at low pressure and density. An ideal gas is a gas that obeys this law.

PV Diagram - Isotherms

Example 17 - 3 What is the volume of 1 mol of an ideal gas at T = 0oC and P = 1 atm?

Example 17 – 4 (1) Initial Volume of gas V1 = 2 L Initial Temperature T1 = 30o C Initial Pressure P1 = 1 atm Final Volume of gas V2 = 1.5 L Final Temperature T2 = 60o C Final Pressure P2 = ?

Example 17 – 4 (2) Remember: must use absolute temperature in gas law

Molar Mass The mass per mole of a substance is called its molar mass (units g/mol) Example – Molar mass of CO2 = molar mass(C) + molar mass(O2) = 12 g/mol + (16 g/mol + 16 g/mol) = 44 g/mol

Example 17 - 6 100 g of CO2 occupies a volume of 55 L at P = 1 atm. What is its temperature? Number of moles: n = m / M = 100 g / 44g/mol = 2.27 mol But T = PV / n R, so T = 295 K

17-5 The Kinetic Theory of Gases

Kinetic Theory of Gases (1) The kinetic theory of gases is a theory that tries to derive the properties of an ideal gas from first principles, in particular, from Newton’s laws.

Kinetic Theory of Gases (2) In a time Dt, on average, ½ the molecules in volume (vx Dt)A are moving right. Therefore, the number of molecules that hit the wall is A

Kinetic Theory of Gases (3) The total change in the x component of the momentum of these molecules is A

Kinetic Theory of Gases (4) The force exerted on the wall is F = Dt / Dt and the pressure P = F/A A

Kinetic Theory of Gases (5) From the kinetic theory one gets A

Kinetic Theory of Gases (6) But since the molecules do not all have the same speed we must replace By the its average value

Kinetic Theory of Gases (7) We now compare the law found experimentally with the formula from the kinetic theory and deduce that

Kinetic Theory of Gases (8) But, given that the average squared speed is we find that

What is Temperature ? From the kinetic theory of gases we have discovered that temperature is a measure of the average kinetic energy of a molecule:

Root Mean Square Speed From we can calculate the rms speed of a molecule

Example 17 – 7 (1) The molar mass of O2 is about 32 g/mol The molar mass of H2 is about 2 g /mol What is the rms speed of O2 and H2 at T = 300 K?

Example 17 – 7 (2) rms speed for O2 is

Example 17 – 7 (3) Since then the rms speed for H2 is given by

Example 17 – 7 (4) So the rms speed for H2 is