Which statement is incorrect?
select one:

a. the volume of solution in the buret should be recorded when the endpoint is reached.
b. it is good practice to place the flask over a white background to better observe the color change of the solution.
c. the endpoint is when the indicator changes color.
d. phenolphthalein will go from a colorless solution to a pink solution for the addition of naoh to an acid solution.
e. when the indicator changes color and remains, 2 more drops of the solution in the buret should be added.

e. When the indicator changes color and remains, 2 more drops of the solution in the buret should be added.

Explanation:

Which statement is incorrect?

Select one:

a. The volume of solution in the buret should be recorded when the endpoint is reached. CORRECT. At the endpoint, the titrant is expected to have completely reacted with the titrand.

b. It is good practice to place the flask over a white background to better observe the color change of the solution.  CORRECT. Using a white background makes it easier to detect the changes in the color of the indicator.

c. The endpoint is when the indicator changes color. CORRECT. This is the function of an indicator.

d. Phenolphthalein will go from a colorless solution to a pink solution for the addition of NaOH to an acid solution.  CORRECT. Phenolphthalein is colorless when pH < 8.3 and it is pink when pH > 10.0.

e. When the indicator changes color and remains, 2 more drops of the solution in the buret should be added. INCORRECT. When the endpoint is reached, no more titrant should be added.