Sections 1 & 2

Section 13-1Section 13.1 The Gas LawsState the relationships among pressure, temperature, and volume of a constant amount of gas. scientific law: describes a relationship in nature that is supported by many experiments Apply the gas laws to problems involving the pressure, temperature, and volume of a constant amount of gas.Explain the difference between a law & a theory?

Section 13-1Section 13.1 The Gas Laws (cont.)Boyles lawabsolute zeroCharless lawGay-Lussacs lawcombined gas lawFor a fixed amount of gas, a change in one variablepressure, temperature, or volumeaffects the other two.What is a variable?

Section 13-1Boyle's LawBoyles law states that the volume of a fixed amount of gas held at a constant temperature varies inversely with the pressure.P1V1 = P2V2 where P = pressure and V = volumeGive an everyday example of Boyles Law.

Section 13-1Charles's LawAs temperature increases, so does the volume of gas when the amount of gas and pressure do not change.Kinetic-molecular theory explains this property.Draw a series of cartoons to show what happens to a filled helium balloon as the temperature gradually increases.

Section 13-1Charles's Law (cont.)What type of mathematical relationship is V vs T ?

Section 13-1Charles's Law (cont.)Absolute zero is zero on the Kelvin scale.Charless law states that the volume of a given amount of gas is directly proportional to its kelvin temperature at constant pressure.Why must all temperatures be put into Kelvin units when using gas laws?

Section 13-1Gay-Lussac's LawGay-Lussacs law states that the pressure of a fixed amount of gas varies directly with the kelvin temperature when the volume remains constant.How does Gay-Lussacs Law apply to NASCAR racing teams?

Section 13-1Gay-Lussac's Law (cont.)What type of mathematical relationship is P vs T ?

Section 13-1If all three laws (Boyles, Charles, Gay-Lussacs) are combined then the resulting equation is the:combined gas lawstates the relationship among pressure, temperature, and volume of a fixed amount of gas.The Combined Gas LawIn the combined gas law formula, draw a circle around Boyles Law, Charles Law & Gay-Lussacs Law. Shade in each circle a different color to distinguish the individual laws that make up the combined law.

When using the combined gas law, cross out any unnecessary variable.Ex) A childs party inflatable has a pressure of 15.8 atm at the beginning of the party when the temperature is 33oC. Near the end of the party the temperature drops to 17oC. What is the new pressure?1st: Convert Celsius temperatures to Kelvin units.Solution:T1 = 33 + 273 = 306 KT2 = 17 + 273 = 290. KThe Combined Gas Law (cont.)

2nd: Substitute values into equation.15.8 atm V1 306 K= P2 V2 290. K3rd: Cross out any variables not mentioned at all.4th: Cross multiply & solve for the unknown.(15.8atm) (290. K) = (306 K) P2 306 K306 KP2 = 15.0 atmThe Combined Gas Law (cont.)

Section 13-1The Combined Gas Law (cont.)

*Explain the difference between a law & a theory?

*What is a variable?*Give an everyday example of Boyles Law.*Draw a series of cartoons to show what happens to a filled helium balloon as the temperature gradually increases.*What type of mathematical relationship is V vs T ?*Why must all temperatures be put into Kelvin units when using gas laws?*How does Gay-Lussacs Law apply to NASCAR racing teams?*What type of mathematical relationship is P vs T ?*In the combined gas law formula, draw a circle around Boyles Law, Charles Law & Gay-Lussacs Law. Shade in each circle a different color to distinguish the individual laws that make up the combined law.****