Monday
July 14, 2014

Homework Help: Chemistry, #5

Posted by Taasha on Saturday, August 4, 2007 at 4:50pm.

For propanioic acid, HC3H5O2, Ka=1.3 x 10^-5, determine the concentration of the species present, the pH and the percent dissociation of a 0.21 M solution. Do this for H+, OH-, C3H5O2-, HC3H5O2, and the pH and percent dissociation.

If someone can please just help me get started!!

Lat's call propanoic acid, HP, to save time on typing. It's a weak acid so it ionizes partially as follows:
HP ==> H^+ + P^-
Initially HP = 0.21 M, (H^+) = 0 and (P^-) = 0.
For every x mole of HP that ionizes, (H^+) will be x and (P^-) will be x. The amount of HP remaining will be 0.2 - x.
Set up Ka.
Ka = (H^+)(P^-)/(HP) = 1.3 x 10^-5
Plug in x for (H^+) and (P^-) and 0.21 - x for (HP). solve for (H^+) and pH. (P^-) = (H^+) and (HP) = 0.21 - x. I will let you finish. Post your work if you get stuck.

I figured out the concentrations, with your help! (thank you), but I am not quite sure how to figure out the percent dissociation. How do I go about this?

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

ap chemistry - For propanoic acid (HC3H5O2, Ka = 1.3 10-5), determine the ...
CHEMISTRY - For propanoic acid (HC3H5O2, Ka = 1.3 10-5), determine the ...
chemistry - 1. if 15.0mL of 4.5 M NaOH are diluted with water to a volume of ...
General Chemistry - Calculate the pH and include the balanced equation for the ...
Chemistry - What must be the molarity of an acetic acid solution if it has the ...
chemistry - A 0.15M solution of weak triprotic acid is adjusted (base added) so ...
Hayden - Chloroacetic acid has a relatively large equilibrium constant, so at ...
chemistry - A 0.15M solution of weak triprotic acid is adjusted (base added) so ...
chemistry - I have no clue, please help and explain! =) Find the pH of a 0.150 M...
Chemistry - Use activity coefficients to find the concentration of hydrogen ions...

Search
Members