Please help me resolving these questions, although I have read instructions seve
ID: 501498 • Letter: P
Question
Please help me resolving these questions, although I have read instructions several times, there aren't much information to learn from
EXPERIMENT 9 ACID AND BASE TITRATION 1 Post-Laboratory Questions i. Indicate the effect each the following procedura stakes on the reported concentration of of the solution. s the reported concentration too high, low, or unaffected? a. The buret rinsed with deionized water and not washed with NaoHusei solution before was being filled for the titration. b. The end point was exceeded by about three drops of titrant. c. A few drops of NaoH solution adhere to the inside of the buret because it was dirty. d. The student did not remove air bulblesfrom the buret tip before reading the initial volume. 2. color, which forms at the point where the NaoH comes into contact with Why does the pink the phenolphthalein in the flask, disappear more slowly near the end point? 3. Why might the color from the indicator slowly disappear even after all acid is titrated? 4. Why is it a good idea to carry out titrations in triplicate? ACID AND BASE TITRATION 1 105
Explanation / Answer
QUESTION 1
a) When using a burette, it is always important to wash it with distilled water and then with the titrant solution. In this case, the volume required will be higher than the actual and this will cause the concentration reported to be higher.
b) When the end point is exceeded the volume reported will be more, leading to a higher concentration than the actual.
c) This won't affect the reported concentration, because the burette records the difference in volumes.
d) This will result in recording a higher volume of the base required to neutralize the acid, in turn increasing the concentration measurement than the actual.