Page 69 - Pharmaceutical_Analytical_Chemistry_1_Theoretical_Notes_Level_1

Mansoura National University
Pharm D-Clinical Pharmacy Program Level 1 Pharm. Anal. Chem. 1 (PC 101)

The pK value of strychnine is 6.0 , calculate the pK of strychnine HCl.
b a
Solution:

pK + pK = pK
a b w
pK = 14 - 6 = 8
a
Calculate the pH of a solution of 4x10 M formic acid (K =1.7x10 ).
-4
-2
a
Solution:

pH = ½ (pK + pC )
a a

-4 -2
pH = - ½ log 1.7x10 – ½ log 4x10 = 2.58
Calculate the pH of 0.1 M ammonia solution. (pK b = 4.75).

Solution
pH = pK w – ½ pK b + ½ log C b
= 14 – 2.38 + (½ log 0.1)
= 11.62 – 0.50 = 11.12

Extra assignment

1. Calculate the pH of 0.06 mol/L HCl?

+
2. Calculate [H ] of a hydrochloric acid solution of pH 5.3
-3
3. Calculate the pH of a 1.05x10 mole/L NaOH solution.
-
-4
+
4. Calculate pH, pOH, [H ] and [OH ] of 3.2x10 M solution of Ba(OH)2.

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