Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
We make two assumptions to calculate the pH of a weak acid. [HA] For example: Find the pH of a 1.50 mol. L-1 solution of HOBr. (HOBr) = 2.40 x 10-9.
Typology: Lecture notes
1 / 11
This page cannot be seen from the preview
Don't miss anything!
How can we calculate the pH of a weak acid? How do we know [H 3 O
] if the solution has not fully dissociated? We use a new constant!! K a HA + H 2
3
3
] [A
a
a
Find the pH of 0.0500 mol.L
3
Workbook pg 231 The pH of a solution of acetic acid is 3.42. What is the concentration of the acid solution? K a
3 COOH) = 1.78 x 10
Sometimes part of a bigger question on buffers/titrations (last topics)
For example: Find the pH of a 0.53 mol.L
Ka(CH 3 COOH) = 1.74 x 10
CH 3
3
NaCH 3 COO Na
] 2 [CH 3
] 2
] = 5. 75 × 10 − 10 × 0. 53 [OH
] = 1.75 x 10
b
w
