CHEM 1031 Lecture Notes - Lecture 5: Ideal Gas Law, Gas Constant, Atmospheric Pressure

• School: Temple University
• Department: Chemistry
• Course: CHEM 1031
• Professor: John B.Michel

Document Summary

Pressure is the force exerted per unit area by gas particles (molecules or atoms) as they strike the surfaces around them. Air: homogeneous mixture of gases: 78% n2, 21% o2, 0. 9% ar, 0. 04% co2, + pollutants. Gas: atoms and molecules random motions: move very fast, various speeds, compressible large distance between them. Units of pressure: (cid:862)at(cid:373)osphe(cid:396)es(cid:863) o(cid:396) (cid:862)at(cid:373)(cid:863) a(cid:396)e ofte(cid:374) used i(cid:374) (cid:272)he(cid:373)ist(cid:396)(cid:455, 101, 325 n/m2= 1 atm, (cid:862)pas(cid:272)al(cid:863) o(cid:396) (cid:862)pa(cid:863, 1 n/m2= 1 pa, 101, 325 pa= 1 atm. Measuring gas pressure: barometer (torricelli 1608-1647) mercury barometer, usually around 760mm, height of column of hg (mercury) in the tube = atmospheric pressure, 760 mmhg = 1 atm, 1 mmhg= 1 torr. Other ways to measure pressure: manometer: u tube filled with hg. Gas laws: 4 physical properties of gases (variants, pressure, p, volume, v, temperature, t, amount, n (amount in moles, all related to each other, (cid:1005).