2Read 11.1 (p. 516 – 519)Draw 3 particle pictures of the different states of matter. Include a container in your diagram.Add symbols to illustrate the motion of the particles.Volunteers?Vgas=VcontainerDefine: KE, TExplain pop can demo.Define: P
3Introduction… Demo 1: Water and Cue Card Demo 2: Pop Can Why does the water stay in the glass?Demo 2: Pop CanWhat is happening in terms of STATES of water?Liquid Gas LiquidWhat is happening in terms of VOLUME of water?Small EXTREMELY LARGE Small1 mol H2O(l)= 18 mL or 0.018L1 mol of H2O(g)= 22.4 L
4We are surrounded by gases! Air (or the Atmosphere) is made up of:This air is colliding with us…this is called PRESSURE…Or specifically the pressure we feel is “Atmospheric Pressure”What would the pressure be like on top of Mount Everest?Pressure: force exerted on an object per unit of surface areaAir pressure= 1 atmosphere= 1 atm
5States of MatterHow do intermolecular forces of attraction differ between states?Generally, how is particle size related to states of matter?CH4 vs. C5H12Larger molecules= higher boiling points= liquid @ room tempWhy???? The bigger the molecule the more opportunities for temporary dipoles to form…dispersion forces add up and this increase the IMF of attractionAre all states compressible?Only gases…what is condensation?
6Types of Kinetic Energy Every moving particle has energy= kinetic energyKinetic=motionSolid= vibrational motionLiquid= rotational and vibrational motionGas= Translational, rotational, and vibrational motion
7Kinetic Molecular Theory of Gases The volume of an individual gas molecule is negligible compared to the volume of the container.*No attractive or repulsive forces between gas molecules.*Gas molecules move randomly in all directions, in straight lines (translational, rotational, vibrational).Perfect elastic collisions between gas molecules (i.e. no loss of kinetic energy).An increase in temperature will increase the motion of molecules. This means there is an increase in the average kinetic energy.* Assumptions for an IDEAL GAS
8What can affect kinetic energy? TEMPERATURE! How? Temperature= Kinetic energyHow is pressure affected? Temperature= Kinetic energy = PressureHow is volume affected? Temperature= Kinetic energy = Pressure= Volume of Gas**space that the gas take up BUT usually Vgas= Volumecontainer* Temperature is a measure of the average kinetic energy
9Pressure The force exerted on an object per unit of surface area P= F = N = PaA m2Pressure: kinetic motion and collisions with surroundingsAtmospheric Pressure is what we feel around us.- Air molecules have a mass.-They are pulled by gravity (acceleration of objects on earth= m/s2 or 32.2 ft/s2) to exert pressure on Earth.
10Units of Pressure Pressure can be measured by: Atmospheres= 1 atm KiloPascals (SI Unit)= kPaMillimeters of Mercury= 760 mmHg (1st mercury barometer)Torricelli’s= 760 torrPounds per square inch (Imperial)= psi1 atm= 101.3kPa= 760 mmHg= 760 torr= psiHow many kPa are in 3.57 atm of pressure?
11Discovering Pressure 760mm ~ 30 inch Barometer= 1st instrument to measure air pressure Torricelli’s Barometer” Torricelli found that air pressure at 0° C 1 atm= 101.3kPa= 760 mmHg= 760 torr= 14.7 psi Standard Temperature and Pressure (STP) 0°C 101.3kPa Standard Ambient Temperature and Pressure (SATP) 25°C 100kPa760mm ~ 30 inch
12Kelvin ScaleK: No negative values!Charles found that the x- intercept would always be - 273°CKelvin (c.1800) inferred that at -273°C VOLUME WOULD BE ZERO (molecular motion would cease, NO kinetic energy)p. 549 #1,20 K= -273°C= “Absolute zero” TK= °C
13Charles’ LawGay-Lussac (c.1800) referenced Charles’ work, and it became known as… Charles’ Law: the volume of a fixed mass of gas is proportional to its temperature (K) when the pressure is kept constantV1 = V2T1 T2T MUST be K!PracticePg. 552 #2
14Boyle’s LawBoyle’s Law (1662): the volume of a given amount of gas at constant temperature, varies INVERSELY with the applied pressureIf we change the pressure by a factor of x, then the volume will change inversely by that same factorMathematically: P1V1= P2V2 p. 559 #1,2
15Gay-Lussac’s Law Recall: 1. Temperature is a measure of average kinetic energy2. Vgas= Volume of containerGay- Lussac’s Law: the pressure of a fixed amount of gas, at constant volume, is directly proportional to its Kelvin temperature.P1 = P2 T1 T2 p. 559 #3MUST use K!PracticePg. 559 Q: 1-3
16Combined Gas Law T MUST be K! Recall: STP 0°C/273K & 101.3kPa SATP 25°C/298K & 100kPa Combine: 1. Bolye’s Law PiVi= PfVf 2. Charles Law Vi = Vf Ti Tf 3. Gay-Lussac’s Law Pi = Pf Ex. A sample of gas has a volume of 150mL at 260K and 92.3kPa. What will the new volume be at 376k and 123 kPa?P1V1 = P2V2 p. 560 #1-3 T1 T2T MUST be K!
17Dalton’s Law of Partial Pressures Ptotal= P1 + P2 + P3 + … +PnImagine mixing 3 different gases each having a different pressure… What would the final pressure be? Dalton’s Law of Partial Pressures: the total pressure of a mixture of gases is the sum of the pressures of each of the individual gases Ex. What is the pressure of O2 in the atmosphere?.21x101.3kPaPracticePg. 594 #1-4Pg. 596 #1-3