16.pH and Ka recitation

# 16.pH and Ka recitation - How is pK b related to pK a c...

This preview shows pages 1–2. Sign up to view the full content.

Chem 105 Nielson Recitation 12/04/07 pH, pOH, pK a , pK b pH (pOH) and calculating K a (K b ) acid or base structure Lewis acid/base 1. pH or pOH calculations a. What is the pH of a 0.029 M H 2 SO 4 solution? b. What is the pOH of a 0.50 M Ca(OH) 2 ? The pH? c. Determine the pH of a 0.0151 M solution of ortho-nitrophenol whose K a = 6.0 x 10 -8 . Note: You can check if your assumption of [H3O+] << [HA] is good, but calculating the % ionization. If the % ionization < 5.0%, then the assumption is good. Go back and calculate % ionization for this reaction. d. What is the pH of a 0.20 M solution of the base CH 3 NH 2 ? K b = 4.2 x 10 -4 . 4. Cooking vinegar is about 1.0 M and has a pH of 2.4. Calculate the K a of the CH 3 COOH in the vinegar. Assume the pH of the solution is only due to the acetic acid.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
5. The K a of CH 2 ClCOOH is 1.4 x 10 -3 . a. What is the pK a of CH 2 ClCOOH? b.
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: How is pK b related to pK a ? c. Write the equilibrium reaction associated with the pK b of this problem and calculate pK b for the reaction. 6. What is the percent ionization of a 5.0 M H 3 PO 4 solution? Use Table 16.3 for K a values for H 3 PO 4 . 7. Think about acid and base structure to answer the following questions. a. Select the stronger acid in each pair and briefly give a chemical reason why it is stronger. (1) HNO 2 HNO 3 (2) CH 2 BrCO 2 H CH 2 ClCO 2 H b. Select the stronger base in each pair and briefly give a chemical reason why it is stronger. (1) CH 3 CH 2 O-CH 3 CH 2 NH-(2) CH 3 OCH 2 NH 2 CH 3 CH 2 NH 2 8. Draw the reaction of the following Lewis acid/base reactions, showing the electrons being accepted/donated. a. – OH + H-Br -------> b. – OH + H 3 C-Br ------->...
View Full Document

## This note was uploaded on 12/09/2009 for the course CHEM 105 taught by Professor Macedone during the Spring '07 term at BYU.

### Page1 / 2

16.pH and Ka recitation - How is pK b related to pK a c...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online