Josie Nadaud
CHM 144L-A
Professor Jessa/TA Jess
October 8, 2015
Experiment 5 Partial Formal Report
Methods
1. Traditional titration with indicator dye (week one)
First the 50mL buret was cleaned by filling it with distilled water and letting it empty three separate times. It was further cleaned by coating the inside with 5 to 10 mL of the 0.0468M NaOH titrant solution and emptying that into the waste beaker as well for three repetitions. 40.0 mL of 7-Up soda was diluted with 60.0 mL of distilled water in a graduated cylinder, and the solution was quantitatively transferred to a 250 mL flask with 5 drops of phenolphthalein indicator. An rapid titration was done to estimate the amount of NaOH necessary to reach equilibrium. For the accurate …show more content…
The buret was then filled to 0.00 mL of 0.0468M NaOH. 20.0 mL of Jones’ Green Apple soda was diluted with 80.0 mL of distilled water and quantitatively moved to a 250 mL beaker. A stir bar was placed in the beaker on a magnetic stir plate, and a clean and calibrated pH probe was suspended in the beaker. A rapid titration was done until the pH was measured at 6.0, then a drop wise titration was record as pH changed by 0.1-0.2 until it reached 10.5. All data was recorded in a lab notebook and kept on the LabQuest. The titration was done to obtain three trials, cleaning the instruments between trials. Data was transferred to a lab computed before clean …show more content…
The equation for the q-test was
Q= (|suspected value—nearest neighbor|)/R, when R=Xlargest—Xsmallest.
NaOH volume at the end point was found by the final buret volume—initial buret volume.
The moles of NaOH were found using the given molarity of 0.0468M and the previously calculated volume.
The moles of citric acid were calculated using stoichiometry of the reaction:
H3C6H5O7 (aq)+ 3OH- (aq) —> 3H20 (l) + C6H5O7 -3
The molarity of citric acid was found from the calculated moles and the measure of volume.
For the modern titration, the equivalence point for mL of NaOH titrant was found using a graph of the first derivative.
The moles of NaOH were found using the estimated equivalence points and the given molarity of 0.0468M through conversion factors.
The moles of citric acid were calculated based on the stoichiometry of the previously stated reaction.
The molarity of citric acid was found from those calculated moles and the measured volume.
Mean molarity was found using the equation sx=(x1+x2+…+xn)/n
The standard deviation was found using the equation Sx=
CHM 144L-A
Professor Jessa/TA Jess
October 8, 2015
Experiment 5 Partial Formal Report
Methods
1. Traditional titration with indicator dye (week one)
First the 50mL buret was cleaned by filling it with distilled water and letting it empty three separate times. It was further cleaned by coating the inside with 5 to 10 mL of the 0.0468M NaOH titrant solution and emptying that into the waste beaker as well for three repetitions. 40.0 mL of 7-Up soda was diluted with 60.0 mL of distilled water in a graduated cylinder, and the solution was quantitatively transferred to a 250 mL flask with 5 drops of phenolphthalein indicator. An rapid titration was done to estimate the amount of NaOH necessary to reach equilibrium. For the accurate …show more content…
The buret was then filled to 0.00 mL of 0.0468M NaOH. 20.0 mL of Jones’ Green Apple soda was diluted with 80.0 mL of distilled water and quantitatively moved to a 250 mL beaker. A stir bar was placed in the beaker on a magnetic stir plate, and a clean and calibrated pH probe was suspended in the beaker. A rapid titration was done until the pH was measured at 6.0, then a drop wise titration was record as pH changed by 0.1-0.2 until it reached 10.5. All data was recorded in a lab notebook and kept on the LabQuest. The titration was done to obtain three trials, cleaning the instruments between trials. Data was transferred to a lab computed before clean …show more content…
The equation for the q-test was
Q= (|suspected value—nearest neighbor|)/R, when R=Xlargest—Xsmallest.
NaOH volume at the end point was found by the final buret volume—initial buret volume.
The moles of NaOH were found using the given molarity of 0.0468M and the previously calculated volume.
The moles of citric acid were calculated using stoichiometry of the reaction:
H3C6H5O7 (aq)+ 3OH- (aq) —> 3H20 (l) + C6H5O7 -3
The molarity of citric acid was found from the calculated moles and the measure of volume.
For the modern titration, the equivalence point for mL of NaOH titrant was found using a graph of the first derivative.
The moles of NaOH were found using the estimated equivalence points and the given molarity of 0.0468M through conversion factors.
The moles of citric acid were calculated based on the stoichiometry of the previously stated reaction.
The molarity of citric acid was found from those calculated moles and the measured volume.
Mean molarity was found using the equation sx=(x1+x2+…+xn)/n
The standard deviation was found using the equation Sx=