CHEM 1A Lecture Notes - Lecture 13: Kinetic Theory Of Gases, Mole Fraction, Torr

• School: UCSB
• Department: Chemistry and Biochemistry
• Course: CHEM 1A
• Professor: BERNT C M

Document Summary

= mol of one species a mixture of gas contains 4 moles of o 2 and 6 moles of n 2. O2 = 4mol /(4mol + 6mol) = 0. 4. Notice : all mole fractions should add up to 1 (since it is 100%) P a = p total x a (where, a represents a component in the total group) We can use this mole fraction to calculate the partial pressure of a component. following the example above, and given that p total = 475 torr (cid:1178) p o2 = 475 torr x 0. 4 = 190 torr. P n2 = 475 torr x 0. 6 = 285 torr. Notes: (1) even though molecules have different speeds, we do have an average speed and thus an average kinetic energy overall, which is the temperature we perceive. Ke avg = (3/2)rt, *where r = 8. 314 j/(mol*k), Note : this average ke does not take into account of the mass of molecules!