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Which flask shows the correct end point color for a phenolphthalein titration?                     I.                                                 II.                                          III.

Increasing the flow rate from 1 to 3 mL/min. may result in a satisfactory separation in one third of the time?

What is the main reason for changing to an isoelutropic mobile phase composition?

(03.02 MC)  Maryann is testing the effectiveness of a new acne medication. There are 100 people with acne in the study. Fifty-five patients received the acne medication, and 45 other patients did not receive treatment. Thirty of the patients who received the medication reported clearer skin at the end of the study. Twenty-two of the patients who did not receive medication reported clearer skin at the end of the study. What is the probability that a patient chosen at random from this study took the medication, given that they reported clearer skin? (5 points)

Which of the following might result in damage to the piston or piston seal? (There may be more than one correct response):

In reversed phase LC:

A solution of sodium hydroxide contained 0.250 mol/dm3. Using phenolphthalein indicator, titration of 25.0 cm3 of this solution required 22.5 cm3 of a hydrochloric acid solution for complete neutralization. What apparatus would you use to measure out the sodium hydroxide solution?

Which of the following statements regarding Binary pumps do you agree with? (select all that apply)

Which of the following will alter analyte retention times when it’s chemical nature is changed? (Note: There may be more than one correct response)

Match the chromatogram to the technique used to generate it.