Question

question 1-3

Page 4 of 4 Part B: Determination of Ascorbic Acid Trial 1 Trial 2 % Ascorbic acid 44.4 % 44.8% 46.9. (747-777² ($9,8-977% (768-787 = 2.5 Trial 3 Average and standard deviation QUESTIONS 1. A student consistently over titrates to a bright pink endpoint. How would this affect a) the precision in part A? b) the accuracy in part A? c) the % ascorbic acid determination (i.e. will it be too high or too low?),

Answer 1

Titration is a quantitative analytical volumetric technique that permits the determination of the unknown concentration of an analyte with a known concentration titrant. This is possible because the two react in a known stoichiometric manner allowing calculation of the unknown concentration.

Here the titration is between a standard solution against Ascorbic acid

The over titration of Ascorbic acid even after the end point will make wrong the calculation of the concentration of the unknown solution.

Accuracy refers to the closeness of measurement to the specific value. Over titration leads to a large difference in actual value to the measured value. Its accuracy is lost

After completing the end point the colour of the solution become brighter and brighter and the same end point may not be possible to speculate each time. So each time the end point of the student will be different. So the precision of the titration will be also wrong i.e., the student is not going to get the same value of concentration or volume at each step. Precision is the closeness of measurements to each other.

With regard to the concentration of ascorbic acid, it will be low from the calculation.