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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: SuPerJC on October 09, 2008, 11:38:10 AM

Title: General question about activity coefficents
Post by: SuPerJC on October 09, 2008, 11:38:10 AM

Problem 1
Calculate activity coefficients for the following ions at the indicated ionic strengths using the Davies equation:
Ca2+ and Cl-; I = 0.06 M
Al3+ and AlOH2+; I = 0.075 M

Problem 2
What is the activity of water in a solution if the vapor pressure of water above the solution is 80% of the vapor pressure of pure water? If the mole fraction of water in this solution is 0.95, what is the activity coefficient for the water?

Problem 3
What assumptions does Essington make when equating Kdiss with Ksp? Under what conditions would these assumptions not be valid?

I took gen chem 3 years ago  and i have no idea with these questions..

Title: Re: General question about activity coefficents
Post by: Borek on October 09, 2008, 12:13:02 PM

http://www.chembuddy.com/?left=pH-calculation&right=ionic-strength-activity-coefficients