Presentation on theme: "Pressure and Volume (Boyle’s Law)"— Presentation transcript:
1Pressure and Volume (Boyle’s Law) Chapter 6 Gases6.3Pressure and Volume (Boyle’s Law)
2Boyle’s Law Boyle’s Law states that the pressure of a gas is inversely related to its volume when T and n are constant.if volume decreases, the pressure increases.
3PV Constant in Boyle’s Law In Boyle’s Law, the product P x V is constant as long as T and n do not change.P1V1 = atm x L = atm LP2V2 = atm x L = atm LP3V3 = atm x L = atm LBoyle’s Law can be stated asP1V1 = P2V2 (T, n constant)
4Solving for a Gas Law Factor The equation for Boyle’s Law can be rearranged tosolve for any factor.P1V1 = P2V Boyle’s LawTo solve for V2 , divide both sides by P2.P1V1 = P2V2P P2V1 x P1 = V2P2
8Calculation with Boyle’s Law Freon-12, CCl2F2, is used in refrigeration systems. What is the new volume (L) of a 8.0 L sample of Freon gas initially at 550 mm Hg after its pressure is changed to 2200 mm Hg at constant T?1. Set up a data table:Conditions 1 Conditions 2P1 = mm Hg P = mm HgV1 = L V2 =?
9Calculation with Boyle’s Law (Continued) 2. When pressure increases, volume decreases.Solve Boyle’s Law for V2:P1V1 = P2V2V = V1 x P1P2V = L x 550 mm Hg = L2200 mm Hgpressure ratiodecreases volume
10Learning Check 1) pressure decreases 2) pressure increases For a cylinder containing helium gas indicate if cylinder A or cylinder B represents the new volume for the following changes (n and T are constant).1) pressure decreases2) pressure increases
11Solution 1) Pressure decreases B 2) Pressure increases A For a cylinder containing helium gas indicate if cylinder A or cylinder B represents the new volume for the following changes (n and T are constant):1) Pressure decreases B2) Pressure increases A
12Learning Check If a sample of helium gas has a volume of 120 mL and a pressure of 850 mm Hg, what is the newvolume if the pressure is changed to 425 mm Hg ?1) 60 mL ) 120 mL 3) 240 mL
13Solution P1 = 850 mm Hg P2 = 425 mm Hg V1 = 120 mL V2 = ?? V2 = V1 x P1 = mL x mm Hg = 240 mLP mm Hg Pressure ratioincreases volume
14Learning CheckA sample of helium gas in a balloon has a volume of 6.4 L at a pressure of 0.70 atm. At 1.40 atm (T constant), is the new volume represented by A, B, or C?
15SolutionA sample of helium gas in a balloon has a volume of 6.4 L at a pressure of 0.70 atm. At a higher pressure (T constant), the new volume is represented by the smaller balloon A.
16Learning Check A) 3.2 L B) 6.4 L C) 12.8 L If the sample of helium gas has a volume of 6.4 L at a pressure of 0.70 atm, what is the new volume when the pressure is increased to 1.40 atm (T constant)?A) 3.2 L B) 6.4 L C) 12.8 L
17SolutionIf the sample of helium gas has a volume of 6.4 L at a pressure of atm, what is the new volume when the pressure is increased to 1.40 atm (T constant)?A) 3.2 LV2 = V1 x P1P2V2 = 6.4 L x atm = L1.40 atmVolume decreases when there is an increase in the pressure (temperature is constant.)
18Learning Check 1) 200. mm Hg 2) 400. mm Hg 3) 1200 mm Hg A sample of oxygen gas has a volume of 12.0 L at 600. mm Hg. What is the new pressure when the volume changes to 36.0 L? (T and n constant).1) mm Hg2) mm Hg3) 1200 mm Hg
19Solution 1) 200. mm Hg Data table Conditions 1 Conditions 2 P1 = mm Hg P2 = ???V1 = L V2 = LP2 = P1 x V1V2600. mm Hg x L = mm Hg L