LEYES DE LOS GASES

Da caluroso

LEYES DE LOS GASES

Da fro

Ley de Charles (1746 - 1823) y

Joseph Gay-Lussac (1778-1850)

V T

V = kT

V1 = kT1 V2 = kT2

k = V1/T1 k = V2/T2

Igualando:

V1/T1 = V2/T2

Charles Gay-Lussa

P y n constantes

LEYES DE LOS GASES

Cambios de presin

Ley de Robert Boyle (1627 - 1691)

P 1/V

P = k(1/V)

P1 = k(1/V1) P2 = k(1/V1)

k = P1V1 k = P2V2

Igualando:

P1V1 = P2V2

T y n constantes

LEYES DE LOS GASES Presin en funcin de la Temperatura

Guillaume Amontons (1663-1705)

P T

P = kT

P1 = kT1 P2 = kT2

k = P1/T1 k = P2/T2

Igualando:

P1/T1 = P2/T2

V y n constantes

LEYES DE LOS GASES

Volumen y Nmero de moles

Ley de Amadeo Avogadro (1776-1856)

V n

V = kn

V1 = kn1 V2 = kn2

k = V1/n1 k = V2/n2

Igualando:

V1/n1 = V2/n2

A 0C y 1 atm, 1 mol de cualquier gas ocupa 22,4 L

T y P constantes

INVOLUCRANDO TODAS LAS VARIABLES:

PRESIN VOLUMEN

TEMPERATURA

Ley de los gases ideales

P 1/V V 1/P

V T

V n

Por lo tanto:

V Tn/P

V = cte. (Tn/P)

V = R (Tn/P)

P1V1 = nRT1 P2V2 = nRT2 nR = P1V1/T1 nR = P1V1/T1

Igualando:

P1V1/T1 = P2V2/T2

Ley de John Dalton (1766-1844) Mezcla de gases

gas A gas B

What are some examples of the gas laws in action in everyday life?

Charles's Law: Doubling the temperature of a gas doubles its volume, as long as the pressure of the gas and the amount of gas isn't changed. A football inflated inside and then taken outdoors on a winter day shrinks slightly. A slightly underinflated rubber life raft left in bright sunlight swells up (Why shouldn't you overinflate your life raft when your ship goes down in tropical waters?) The plunger on a turkey syringe thermometer pops out when the turkey is done (The volume of air trapped under the plunger increases when the temperature inside the turkey climbs). Boyle's Law: Doubling the pressure on a gas halves its volume, as long as the temperature of the gas and the amount of gas aren't changed. The bubbles exhaled by a scuba diver grow as the approach the surface of the ocean. (The pressure exerted by the weight of the water decreases with depth, so the volume of the bubbles increases as they rise.) Deep sea fish die when brought to the surface. (The pressure decreases as the fish are brought to the surface, so the volume of gases in their bodies increases, and pops bladders, cells, and membranes). Pushing in the plunger of a plugged-up syringe decreases the volume of air trapped under the plunger.

Amontons' Law: Doubling the temperature of a gas doubles its pressure, if the volume and the amount of gas aren't changed.. The gauge pressure in a steel-belted automobile tire will be higher when the car is traveling over hot asphalt than it was when the car was in the garage. Throwing an aerosol can into a fire may cause it to explode. Avogadro's Law: Doubling the number of moles of gas doubles its volume, if temperature and pressure aren't changed. A flat tire takes up less space than an inflated tire. Lungs expand as they fill with air. Exhaling decreases the volume of the lungs. A balloon filled with helium weighs much less than an identical balloon filled with air. (Avogadro's Law implies that equal volumes contain equal numbers of molecules, when pressure and temperature are held constant. Since both balloons contain the same number of molecules, and since helium atoms have lower mass than either oxygen molecules or nitrogen molecules in air, the helium balloon is lighter.) Wet air is less dense than moist air (see the FAQ on gases for an explanation).

Ley de los gases ideales

Gas hipottico cuyo comportamiento de P, V y T se puede describir completamente con la ecuacin del gas ideal.

Caractersticas: Las molculas no se atraen

o repelen entre s. Su volumen es

despreciable en comparacin con el volumen del recipiente que lo contiene

1834 Emil Clapeyron