2 Learning 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.
3 Boyle’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
5 Connection 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”
6 P1V1 = 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.
7 Boyle’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??
8 Boyle’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)
9 Charles’ 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
11 Charles’s Law: Formula V1T1V2T2=V1 = initial volumeT1 = initial temperatureV2 = final volumeT2 = final temperatureIf you know three of the four, you can calculate the fourth.
12 Charles’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( )
13 Gay-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
15 Gay-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.
16 Gay-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( )
18 The Combined Gas LawThe combined gas law expresses the relationship between pressure, volume and temperature of a fixed amount of gas.
19 Sample 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 = ??
20 Pressure, Volume, Temperature Let’s see what we already know about these three variables …Gas Law Program
21 NOVA: Race for Absolute Zero Try not to lose your head when you are doing chemistryandWhy you should always wear your safety goggles