- Water And Ph Chemistry Worksheet (Page 4 of 4) in pdf

- Water And Ph Chemistry Worksheet Page 4

What is the H-H Equation Used For?

This is used to determine the concentration of acid and base at a given pH. It is Also used to determine the pH of a

known solution. These concepts are used to calculate buffer strength and understand the pH of a biological solution.

Remember that buffers are mixtures of weak acids and their conjugate bases that resist pH by shifting the

equilibrium between the acid and base in response to the pH of a solution.

Case 1) when the concentration of base equals the acid.

Case 2) when the pH is above or below 1 pH unit of the pKa

Calculate the pH of a mixture of 250 mM acetic acid and 100 mM Na acetate. The pKa of acetic acid is 4.75.

Start with the HH equation

What is the ratio of lactic acid to lactate in a buffer at pH of 5.00.

The pKa of lactic acid is 3.86?

•

What is the concentration of base and acid you need to add to make a 50 mM solution of lactate buffer at pH

4.0? The MW of Lactic acid is 91 amu and sodium lactate is 102 amu.

This is for you to take home try and we will calculate an answer with Dr Provost -!

- Water And Ph Chemistry Worksheet Page 4