Measuring the Pressure of a Gas and Gas Laws of Boyle, Charles and Avogadro Chemistry 142 B Autumn Quarter, 2004 J. B. Callis, Instructor Lecture #13.

Slides:



Advertisements
Similar presentations
Gases An Exploration in Ideal Gas Behavior Loosely adapted from: Philip Dutton University of Windsor, Canada and Martin Silberberg.
Advertisements

Gases Chapter 13 Page 298. Gases Properties: Gases are fluids because their molecules/atoms can flow Gases have low density Highly compressible – their.
Not so long ago, in a chemistry lab far far away… May the FORCE/area be with you.
Not so long ago, in a chemistry lab far far away… May the FORCE/area be with you.
Chapter 11 Gas Laws. The Gas Phase Gases have no distinct volume or shape. Gases expand to fill the volume of their container. Gas particles are miscible.
Gases Laws Notes. Pressure Pressure- force per unit area caused by particles hitting the walls of a container Barometer- Measures atmospheric pressure.
Gas Laws.
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 1 Gases.
Drill 4/16/2015 What do you think is the oldest form of human flight? How does it work?
Gas Law and Gas Behavior
The Ideal Gas Law and Stoichiometry Chemistry 142 B Autumn Quarter, 2004 J. B. Callis, Instructor Lecture #14.
Not so long ago, in a chemistry lab far far away… May the FORCE/area be with you.
May 7, 2012 HONORS CHEMISTRY Brain Teaser Turn in Titration Lab Describe the characteristics or properties of solid, liquid and gases.
Chapter 11 Gases.
Chapter 6 Gases 6.1 Properties of Gases.
Chapter 13: Gases. What Are Gases? Gases have mass Gases have mass.
Section 13.1 Describing the Properties of Gases 1.To learn about atmospheric pressure and how barometers work 2.To learn the units of pressure 3.To understand.
Catalyst Review your Mock AP exam score and complete the reflection sheet Turn into bin when completed.
1 Chapter 5: GASES. 2  In this chapter we will:  Define units of pressure and volume  Explore the properties of gases  Relate how the pressure, volume,
Chapter 12: The Behavior of Gases. Think of Chem 1A…. Mrs. Richards, Mr. Mazurek, Ms. Knick, Ms. Olin….. What do you remember about gases????
5-1 Copyright ©The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 10 Gases Lecture Presentation.
Gases: Their Properties and Behavior
Gas Laws.
Gases Gases and Pressure Gases – constituent atoms and molecules that have little attraction for one another Free to move in available volume Some.
GAS LAWS. Properties of Gases  Composed of randomly scattered particles  No definite _________ or ___________  Spread out to fill the space of their.
Gases Chapter 13 Some basics Gases have properties that are very different from solids and liquids. Gases have properties that are very different from.
5-1 Copyright ©The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Today’s Quiz What is a gas (in chemistry)? 2.Mention.
Chapter 11: Gases. © 2009, Prentice-Hall, Inc. Characteristics of Gases Unlike liquids and solids, gases – expand to fill their containers; – are highly.
Unit 5: Gases and Gas Laws. Kinetic Molecular Theory  Particles of matter are ALWAYS in motion  Volume of individual particles is  zero.  Collisions.
GASES and the Kinetic Molecular Theory A.Gas particles DO NOT attract or repel each other B.Gas particles are much smaller than the distances between them.
Chapter 13: Gases. What Are Gases? Gases have mass Gases have mass Much less compared to liquids and solids Much less compared to liquids and solids.
Nature of Gases 1 – gases have mass (low density) 2 – particles glide past one another (flow) - fluid 3 – easily compressed 4 – fill containers completely.
Gas Laws By: Ms. Buroker. Gas Laws Gas Laws explores the relationships between: Volume, V … Liters Temperature, T … Kelvin Amount, n … moles Pressure,
Chapter 10; Gases. Elements that exist as gases at 25 0 C and 1 atmosphere.
CLE Apply the kinetic molecular theory to describe solids, liquids, and gases. CLE Investigate characteristics associated with the gaseous.
Chapter 9 Gases: Their Properties and Behavior. Gases and Gas Pressure Gas mixtures are homogeneous and compressible.
GASES Chapter 10. The Atmosphere The atmosphere is a gaseous solution of nitrogen, N 2, and oxygen, O 2. The atmosphere both supports life and acts as.
Gases. Properties: Gases are fluids because their molecules/atoms can flow Gases have low density - atoms are far apart from each other Highly compressible.
Chapter 6 Gases 6.1 Properties of Gases.
KINETIC MOLECULAR THEORY Physical Properties of Gases: Gases have mass Gases are easily compressed Gases completely fill their containers (expandability)
Gases. Kinetic Theory of Gases Explains Gas behavior: 4 parts: 1) Gas particles do not attract or repel each other (no I.M. forces).
Gases Properties of gases and gas laws. Chapter 14.
 5.1 Substances that exist s gases  5.2 Pressure of the gas  5.3 The gas laws  5.4 Ideal gas equation  5.5 Gas stoichiometry  5.6 Dalton’s Law of.
Chapter Five Gases. Chapter Five / Gases Substances That Exist as Gases Element in blue are Gases Noble gases are monatomic All other gases (H 2, N 2,
Gases HW: read CH 13.
Introduction to Gases Earth is surrounded by a layer of gaseous molecules - the atmosphere - extending out to about 50 km.
Properties of Gases Kinetic Molecular Theory: 1.Small particles (atoms or molecules) move quickly and randomly 2.Negligible attractive forces between particles.
Houston Community College System Chemistry 1405 Chapter 5 The Physical Properties of Gases By Mounia Elamrani Blei / Odian ’ s General, Organic, and Biochemistry.
DO NOW List 5 gases that you can think of without the aide of a book. Classify these gases are either elements, compounds or mixtures. Explain your classifications.
GASES Chapter 12 in your text book. KINETIC-MOLECULAR THEORY OF GASES Gas particles are in constant random and rapid motion. The space between gas molecules.
Gases AP Chemistry Mr. G. All matter follows the KMT: Kinetic Molecular Theory KMT- the tiny particles in all forms of matter are in constant motion.
GASES Unit 10. KINETIC-MOLECULAR THEORY OF GASES 1.Gases consist of tiny atoms or molecules that are in constant random motion. 2.The space between gas.
Chapter 11 Gases. Pressure and Force ____________ (P): the force per _________ on a surface. ________ (N): the force that will increase the speed of a.
PRACTICE AND REVIEW GAS LAWS. STUDENT LEARNING OBJECTIVES 1.Define pressure. Identify units of pressure and make conversions between appropriate pressure.
Gases Pressure (5.1) Gas Laws of Boyle, Charles, Avogadro (5.2) Ideal Gas Law (5.3) Gas Stoichiometry (5.4) Kinetic Molecular Theory (5.6) Effusion & Diffusion.
Chapter 10 Gases.
The Behavior of Gases.
Unit 5 - Gases Objective :
Chapter 14 – Gas Laws.
Gases.
Chapter 5 Gases.
Chapter 11 Gas Laws.
Chapter 10 Gases.
Lecture Presentation Chapter 10 Gases.
Chemistry 1411 Joanna Sabey
Gas Laws
The Behavior of Gases.
Ch.14: Gas Laws Part 1.
GASES and the Kinetic Molecular Theory
Presentation transcript:

Measuring the Pressure of a Gas and Gas Laws of Boyle, Charles and Avogadro Chemistry 142 B Autumn Quarter, 2004 J. B. Callis, Instructor Lecture #13

The Three States of Matter for the Element Bromine

Important Characteristics of Gases 1) Gases are highly compressible An external force compresses the gas sample and decreases its volume: removing the external force allows the gas volume to increase. 2) Gases are thermally expandable When a gas sample is heated, its volume increases. When it is cooled its volume decreases. 3) Gases have low viscosity Gases flow much easier than liquids or solids. 4) Most Gases have low densities Gas densities are on the order of grams per liter whereas liquids and solids are grams per cubic cm, 1000 times greater. 5) Gases are infinitely miscible Gases mix in any proportion such as in air, a mixture of many gases.

Helium He 4.0 Neon Ne 20.2 Argon Ar 39.9 Hydrogen H Nitrogen N Nitrogen Monoxide NO 30.0 Oxygen O Hydrogen Chloride HCl 36.5 Ozone O Ammonia NH Methane CH Substances that are Gases under Normal Conditions Substance Formula MM(g/mol)

Pressure of the Atmosphere Called “atmospheric pressure,” or the force exerted upon us by the atmosphere above. A measure of the weight of the atmosphere pressing down upon us. Measured using a barometer - A device that can weigh the atmosphere above us.

The Effect of Atmospheric Pressure on objects at the earth’s surface

A Mercury Barometer

Construct a Barometer using Water Density of water = Density of Mercury = Height of water column = H w H w = H w =

A Closed End Manometer

An Open ended Manometer

A J-tube similar to the one used by Boyle

Common Units of Pressure Unit Atmospheric Pressure Scientific Field pascal (Pa); x 10 5 Pa SI unit; physics, kilopascal(kPa) kPa Chemistry atmosphere (atm) 1 atm* Chemistry millimeters of mercury 760 mmHg* Chemistry, medicine, ( mm Hg ) biology torr 760 torr* Chemistry pounds per square inch 14.7 lb/in 2 Engineering ( psi or lb/in 2 ) bar bar Meteorology, chemistry, physics

Problem 13-1: Converting Units of Pressure Problem: A chemist collects a sample of Carbon dioxide from the decomposition of limestone (CaCO 3 ) in a closed end manometer, the height of the mercury is mm Hg. Calculate the CO 2 pressure in torr, atmospheres, and kilopascals. Plan: The pressure is in mmHg, so we use the conversion factors from The preceding table to find the pressure in the other units. Solution: (a) P CO2 (torr) = converting from mm Hg to torr: converting from torr to atm: (b) P CO2 ( atm) = converting from atm to kPa: (c) P CO2 (kPa) =

Boyle’s Law : P - V Relationship Pressure is inversely proportional to volume at fixed temperature and fixed amount: P = or V = or PV=K KVKV KPKP Where: P is the pressure exerted by the sample on the surroundings. V is the volume occupied by the sample. K is a constant of proportionality.

Problem 13-2: Applying Boyles Law Problem: A gas sample at a pressure of 1.23 atm has a volume of 15.8 cm 3, what will be the volume if the pressure is increased to 3.16 atm? Plan: We begin by converting the volume that is in cm 3 to mL and then to liters, then we do the pressure change to obtain the final volume. Solution: V 1 (cm 3 ) V 1 (ml) V 1 (L) V 2 (L) 1cm 3 = 1 mL 1000mL = 1L x P 1 /P 2 P 1 = 1.23 atm P 2 = 3.16 atm V 1 = 15.8 cm 3 V 2 = unknown T and n remain constant V 1 = V 2 =

Deviations From Boyle’s Law

Extrapolation of PV Data to Zero Pressure Yields Ideal Behavior

Charles’s Law : V - T Relationship Volume is directly proportional to temperature at fixed pressure and fixed amount: V = CT or = C V T Where: V is the volume occupied by the sample. T is the temperature in degrees Kelvin. C is a constant of proportionality.

Charles’s Law Behavior for Several Gases

Problem 13-3: Charles Law A sample of carbon monoxide, a poisonous gas, occupies 3.20 L at 125 o C. Calculate the temperature ( o C) at which the gas will occupy 1.54 L if the pressure remains constant. V 1 = T 1 = V 2 = T 2 = T 2 = T 2 = o C =

Problem 13-4: Amonton’s Law Problem: A copper tank is compressed to a pressure of 4.28 atm at a temperature of o F. What will be the pressure if the temperature is raised to 95.6 o C? Plan: The volume of the tank is not changed, and we only have to deal with the temperature change, and the pressure, so convert to SI units, and calculate the change in pressure from the Temp.and Pressure change. Solution: T 1 = T 2 = P 2 =

Avogadro’s Law : V - n Relationship Volume is directly proportional to moles of gas at fixed pressure and temperature: V = Bn or = B V n Where: V is the volume occupied by the sample. n is the number of moles of gas. B is a constant of proportionality.

Problem 13-5: Avogadro’s Law Problem: Sulfur hexafluoride is a gas used to trace pollutant plumes in the atmosphere, if the volume of 2.67 g of SF 6 at atm and 28.5 o C is 2.93 m 3, what will be the mass of SF 6 in a container whose volume is m 3 at atm and 28.5 o C? Plan: Since the temperature and pressure are the same, it is a V - n problem, so we can use Avogadro’s Law to calculate the moles of the gas, then use the molecular mass to calculate the mass of the gas. Solution: Molar mass SF 6 = g/mol

Standard Temperature and Pressure (STP) A set of Standard conditions have been chosen to make it easier to understand the gas laws, and gas behavior. Standard Temperature = 0 0 C = K Standard Pressure = 1 atmosphere = 760 mm Mercury At these “standard” conditions 1.0 mole of a gas will occupy a “standard molar volume”. Standard Molar Volume = Liters = 22.4 L

Answers to Problems in Lecture # torr, atm, kPa L o C atm g SF 6