Class Notes (834,889)
United States (323,963)
Chemistry (249)
CHEM 111 (69)
Lecture

# Standard conditions, gas constant (R), gas law and density, gas mixtures, mole fraction (X)

3 Pages
59 Views

Department
Chemistry
Course
CHEM 111
Professor
Dana Johnson
Semester
Fall

Description
3 November Announcements Practice exam tonight Here, A103 7 – 9 pm Mid-semester grade check Please check to make sure all your grades are posted Let me know if something is missing Standard conditions Once P, V, T and n were all related, a constant was needed Standard states had to be specified: P = 1 atm T = 273.15 K (or 0° C) n = 1 mole V = 22.4 L STP conditions – standard temperature and pressure 1 mole in 1 liter How is this possible? Same # of particles But different weights → different average speeds Gas constant, R Determination of R: (1 atm x 22.4141 L) / (1 mol x 273.15 K) 0.08205 Note units of (atm x L) / (mol x K) How R is used to relate the equation: PV = nRT ideal gas law R = P V / n T initial 1 1 1 1 R = P V2/2n T 2 2 final P 1 1 n T1=1P V / n2T2 2 2 Example A rigid plastic container holds 35.0 g of ethylene gas at a pressure of 793 torr. What is the pressure if 5.0 g of ethylene is removed at constant temperature? P / n = P / n 1 1 2 2 793 torr / 35 g = P / 32 g P 2 P n1/ 2 1 P 2 793 (30) / 35 P = 680 torr
More Less

Related notes for CHEM 111
Me

OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Join to view

OR

By registering, I agree to the Terms and Privacy Policies
Just a few more details

So we can recommend you notes for your school.