2Learning ObjectivesUnderstand the qualitative relationship between pressure (P) and volume (V) and temperature (T), when you have a gasLearn the three gas laws and how to apply them mathematically to solve problemsCombine the gas laws into one equation, and solve problems where P, V, and T are no longer constant.
3Boyle’s LawRobert Boyle, studied the relationship between pressure, p, and volume, V, in the mid-1600s.When he doubled the pressure on a sample of gas at constant temperature, its volume was reduced by one-half.pressurevolume
5Connection To Your Math Class Asymptote- A line that continually approaches a given curve but does not meet it at any finite distance.Greek word that means “not falling together”
6P1V1 = P2V2 Boyle’s Law: Formula P1 = initial pressureV1 = initial volumeP2 = final pressureV2 = final volumeIf you know three of the four, you can calculate the fourth.
7Boyle’s Law: Sample Problems P1V1 = P2V2Standard ProblemA sample of oxygen gas has a volume of 150. ml when its pressure is atm. What will the volume of the gas be at a pressure of atm if the temperature does not change?More Difficult ProblemIt is hard to begin inflating a balloon. A pressure of kPa is required to initially inflate the balloon mL. What is the final pressure in mm Hg when the balloon has reached it's capacity of 1.2 L??
8Boyle’s Law: Sample Problem P1V1 = P2V2A sample of oxygen gas has a volume of 150. ml when its pressure is atm. What will the volume of the gas be at a pressure of atm if the temperature does not change?P1 = atmV1 = 150. mlP2 = atmV2 = what problem is looking forP1V1 = P2V2P2 = P2P1V1 = V2P2V2 = (0.947)(150.) = 144 ml of O2(.987)
9Charles’ LawJacques Charles discovered the relationship between volume and temperature in 1787.The law states that the volume of a sample of gas at constant pressure varies directly with Kelvin temperature.volumetemperaturest hydrogen balloon
11Charles’s Law: Formula V1T1V2T2=V1 = initial volumeT1 = initial temperatureV2 = final volumeT2 = final temperatureIf you know three of the four, you can calculate the fourth.
12Charles’s Law: Sample Problem V1T1V2T2=A sample of neon gas occupies a volume of 752 ml at 25oC. What volume will the gas occupy at 50oC if the pressure remains constant?T2V T2V2T T2T2V1T1==V2V2 = (752)( ) = 815 ml Ne( )
13Gay-Lussac’s LawJoseph Gay-Lussac is credited with discovering relationship between pressure and temperature, but the discovery should actually go to Guillaume Amontons (1699).There is a Gay-Lussac's law but it has to do with the ratio of the volumes of gases in a chemical reaction, the "law of combining volumes".pressuretemperature
15Gay-Lussac’s Law: Formula P1T1P2T2=P1 = initial pressureT1 = initial temperatureP2 = final pressureT2 = final temperatureIf you know three of the four, you can calculate the fourth.
16Gay-Lussac’s Law: Sample Problem T1P2T2=The gas in an aerosol can is at a pressure of 3.00 atm at 25oC. The can warns not to allow the temperature to get above 52oC. What would the pressure of the can be at 52oC?T2P T2P2T T2T2P1T1==P2P2 = (3.00)( ) = atm( )
18The Combined Gas LawThe combined gas law expresses the relationship between pressure, volume and temperature of a fixed amount of gas.
19Sample Combined Gas Law Problem A sample of helium gas has a volume of L, a pressure of atm and a temperature of 29°C. What is the new temperature (°C) of the gas at a volume of 90.0 mL and a pressure of 3.20 atm?Set up Data TableP1 = atm V1 = 180 mL T1 = 302 KP2 = atm V2= 90 mL T2 = ??
20Pressure, Volume, Temperature Let’s see what we already know about these three variables …Gas Law Program
21NOVA: Race for Absolute Zero Try not to lose your head when you are doing chemistryandWhy you should always wear your safety goggles