Titration, please explain why?
Using 0.1 M NaOH to titrate 5 mL of liquid extracted from a fermented milk sample. Since the liquid is chunky white, 25 mL of distilled water would be added to diltute the color. At the end the molarity of lactic acid is calculated by the following equation: Molarity of acid x Volume of acid = Molarity of base x Volume of base.
Would the 25 mL of water affect the result?
Using 0.1 M NaOH to titrate 5 mL of liquid extracted from a fermented milk sample. Since the liquid is chunky white, 25 mL of distilled water would be added to diltute the color. At the end the molarity of lactic acid is calculated by the following equation: Molarity of acid x Volume of acid = Molarity of base x Volume of base.
Would the 25 mL of water affect the result?
1 Answer
It depends on the result you want.
Explanation:
The added water will not affect the calculation of the molarity if you account for the dilution of the sample.
Assume that the original 5 mL of sample contained 0.001 mol of lactic acid HLac).
Its original concentration was
If you add 25 mL of water, its new concentration will be
These are the concentrations you would get by titration.
However, you remember that you diluted the original solution by a factor of 6.
You then multiply the concentration of the dilute solution by 6 and find that the concentration of the original solution was
Thus, the concentrations will be different in the two solutions, but you can make the appropriate corrections.
