III. Questions . 1.During the titration several milliliters of deionized water a
ID: 992035 • Letter: I
Question
III. Questions.
1.During the titration several milliliters of deionized water are added to the Erlenmeyer flask containing the KHP solution. How will this affect the calculated concentration of NaOH (too high, too low, or unchanged?) Explain clearly.
2.A 25.00 mL volumetric pipet is rinsed with deionized water. Several drops of water remain in the pipet. It is then used to deliver a 25.00 mL aliquot of the KHP solution into the Erlenmeyer flask in which the sample will be titrated. How will this affect the calculated concentration of NaOH (too high, too low, or unchanged?) Explain clearly.
3.A buret is cleaned and rinsed with deionized water. Some water remains in the buret. It is then filled with the NaOH solution which is being standardized. How will this affect the calculated concentration of NaOH (too high, too low or unchanged?) Explain clearly.
4.During the preparation of the KHP solution, some KHP is spilled on the counter. How will this affect the calculated concentration of NaOH (too high, too low, or unchanged?) Explain clearly.
Explanation / Answer
1) Addition of water does not change the number of moles of KHP in the flask, hence the calculated strength of NaOH will remain unchanged
2) In this case the KHP solution is diluted, so volume of NaOH required will be lower than actual volume. So the calculated concentration of NaOH will be higher than actual.
3) In this case the NaOH solution is diluted, hence more of it will be required than actually would have been. So the calculated concentration of NaOH will be lower than actual.
4) This has no effect on the concentration of the KHP solution, hence calculated concentration of NaOH will remain unchanged.