Editing revision 7 of PHScale

ChemistryWiki | RecentChanges | Preferences

Editing old revision 7. Saving this page will replace the latest revision with this text.

<center>pH Scale</center>
 
 
 
From the handout on pH scale (given during class) or from the website listed below, pH indicates the relative concentration of the hydronium ion ([H+] or [H3O+]). It is not the concentration of the acid molecule, <nowiki>[HA]</nowiki>. Since strong acids and weak acids ionize to different extent, you need to handle them different with respect to pH calculations. 
 
pH with strong acids 
 
Since strong acid ionize 100%, you can use stoichiometry to figure out the hydronium ion concentration ([H+] or [H3O+]). Once you find the hydronium ion concentration, you can use the pH equation given in the other handout or website below to determine the pH of the solution. 
 
Example:What is the pH of a 0.025M <nowiki>HCl</nowiki> solution. 
 
As with all stoichiometry problem, you must writedown chemical reaction, <nowiki> 
1 HCl + 1 H2O --> 1 H3O+ + Cl1- 
So (0.025M <nowiki>HCl</nowiki>)(1mole H3O+ / 1 mole <nowiki>HCl</nowiki>) = 0.025M H3O+ 
 
*[http://www.chem.ubc.ca/courseware/pH/index.html Good notetaking website (www.chem.ubc.ca) for pH scale. Click on the Dissociation of Water and the pH scale]

View other revisions
ChemistryWiki | RecentChanges | Preferences