Problem:

You are studying the effects of the enzyme alcohol dehydrogenase (ADH) on the oxidation of ethanol to acetaldehyde using a spectrophotometer. Your first step is to set up some reaction mixtures in cuvettes.

Question 1: In the first cuvette, you add 0.45 mL of ethanol (0.16 M) to a reaction mixture containing several other reagents, which brings the final volume of the solution to 3.0 mL. Calculate the final concentration of ethanol.

Question 2: Next, you need to make a 3.0 mL solution containing ethanol with a final concentration of 0.033 M. Using a stock solution of 0.16 M ethanol, what volume of ethanol must you add to create this solution?

Question 3: In another cuvette, you add 0.5mL of pyrophosphate buffer (pH 8.5, 0.06 M) to bring the final volume of the solution to 3.0 volume of the solution to 3.0 mL. What is the final concentration of buffer?

Please show your calculations.