ii. the gas laws boyles charles gay- lussac ch. 12 - gases

II. The Gas LawsBOYLES

CHARLESGAY-

LUSSAC

Ch. 12 - GasesCh. 12 - Gases

A. Boyle’s LawA. Boyle’s LawThe pressure and volume of

a gas are inversely related • at constant mass & temp

P

V

P1V1=P2V2

A. Boyle’s LawA. Boyle’s Law

V

T

B. Charles’ LawB. Charles’ LawThe volume and absolute

temperature (K) of a gas are directly related • at constant mass & pressure

V1 =V2

T1 = T2

B. Charles’ LawB. Charles’ Law

P

T

C. Gay-Lussac’s LawC. Gay-Lussac’s LawThe pressure and absolute

temperature (K) of a gas are directly related • at constant mass & volume

P1 = P2 T1 T2

D. Combined Gas LawD. Combined Gas Law

P1V1

T1

=P2V2

T2

P1V1T2 = P2V2T1

GIVEN:V1 = 100. mL

P1 = 150. kPa

V2 = ?

P2 = 200. kPa

WORK:P1V1T2 = P2V2T1

E. Gas Law ProblemsE. Gas Law ProblemsA gas occupies 100. mL at 150.

kPa. Find its volume at 200. kPa.

BOYLE’S LAWP V

(150.kPa)(100.mL)=(200.kPa)V2

V2 = 75.0 mL

GIVEN:V1 = 473 cm3

T1 = 36°C = 309K

V2 = ?

T2 = 94°C = 367K

WORK:P1V1T2 = P2V2T1

E. Gas Law ProblemsE. Gas Law ProblemsA gas occupies 473 cm3 at 36°C.

Find its volume at 94°C.

CHARLES’ LAWT V

(473 cm3)(367 K)=V2(309 K)

V2 = 562 cm3

GIVEN:P1 = 765 torr

T1 = 23°C = 296K

P2 = 560. torr

T2 = ?

WORK:P1V1T2 = P2V2T1

E. Gas Law ProblemsE. Gas Law ProblemsA gas’ pressure is 765 torr at 23°C.

At what temperature will the pressure be 560. torr?

GAY-LUSSAC’S LAWP T

(765 torr)T2 = (560. torr)(309K)

T2 = 226 K = -47°C

F. STPF. STP

Standard Temperature & PressureStandard Temperature & Pressure

0°C 273 K

1 atm 101.325 kPa-OR-

STP

GIVEN:V1 = 7.84 cm3

P1 = 71.8 kPaT1 = 25°C = 298 KV2 = ?P2 = 101.325 kPaT2 = 273 K

WORK:P1V1T2 = P2V2T1

(71.8 kPa)(7.84 cm3)(273 K)=(101.325 kPa) V2 (298 K)

V2 = 5.09 cm3

E. Gas Law ProblemsE. Gas Law ProblemsA gas occupies 7.84 cm3 at 71.8 kPa &

25°C. Find its volume at STP.

P T VCOMBINED GAS LAW

SolveSolve Divers get “the bends” if they come up

too fast because gas in their blood expands, forming bubbles in their blood. If a diver has 0.05 L of gas in his blood under a pressure of 250 atm, then rises instantaneously to a depth where his blood has a pressure of 50.0 atm, what will the volume of gas in his blood be? Do you think this will harm the diver?

SolveSolveOn hot days, you may have noticed

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SolveSolveA gas is heated from 263.0 K to

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SolveSolveA gas with a volume of 4.0L at a

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SolveSolveA gas has a pressure of 699.0 mm

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SolveSolve I have added 15 L of air to a

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