Lab #5 Titration_Grewal

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Name: Preetjot Grewal Lab Partner: Dennis Love Section: 117 Lab Assignment #5 Table 1: Vinegar Titration Results Volume NaOh (mL) Moles NaOh Moles CH3CO2H Molarity CH3CO2H (M) % (M/V) 16.9 0.00167 0.00167 0.0835 5.01 16.8 0.00166 0.00166 0.830 4.98 17 0.00168 0.00168 0.840 5.04 Average 0.5845 5.01 Table 2: White Gatorade Titration Results Volume NaOH (mL) Moles NaOH Moles H3C6H5O7 Molarity H3C6H5O7 (M) % (M/V) 1.7 0.000168 0.000056 0.0056 0.108 3.5 0.000346 0.000115 0.0115 0.221 3.5 0.000346 0.000056 0.0115 0.221 Average 0.00953 0.183 Questions: 1. Compare to ‘accepted’ results, by either using the label of the vinegar bottle and/or looking up reported % of acetic acid in vinegar. Discuss the validity of your results. Do they make sense, can they be trusted, do you think more titrations should be completed? The accepted value of acetic acid in vinegar according to google is 5%. The validity of our results is very precise as the % M/V are all very close to the value of 5%. They make sense and they can be trusted because of their precision. 2. What was your hypothesis (question 5 of pre-lab questions) and did your hypothesis match your experimental results, explain. My hypothesis was that out of the two samples, vinegar and Gatorade, the one that has a higher acid content is vinegar. My experiment results ended up being correct because according to my data the molarity of acetic acid from all three trials was a higher amount than the molarity of the citric acid. 3. Coca Cola contains phosphoric acid ( H3PO4 ). The reaction of phosphoric acid with sodium hydroxide is given by the reaction: H3PO4 (aq) + 2NaOH (aq) → Na2HPO4 (aq) + 2H2O Note it reacts in a 1:2 mole ratio with sodium hydroxide.

Name: Preetjot Grewal Lab Partner: Dennis Love Section: 117 Lab Assignment #5 A student measured the acid content of a 10 ml sample of Coca Cola using 0.1234 M NaOH. The student performed 3 titrations and found the average volume needed for each titration was 4.35 ml. Calculate the molarity of phosphoric acid in Coca Cola, and the % w/v. Show your work (5.3679 × 10 −4 ?𝑜? ?𝑎?𝐻) 1 × (1 ?𝑜? 𝐻 3 ?? 4 ) (2 ?𝑜? ?𝑎?𝐻) ? = (2.68 × 10 −4 ?𝑜? 𝐻 3 ?? 4 ) 0.00435 ? ? = 0.0617 ? 𝐻 3 ?? 4 % ? ? = 0.0617 × 97.977 𝑔 ?𝑜?𝑎? ?𝑎?? = 6.05 (6.05 × 1000(??)) 100 = 0.605% 4. Write a short formal summary of this lab. Clearly state what was titrated, and the molarity of the titrant. Then include the molarity and %w/v found for each acid, in the sample tested. Also, comment on the reliability of the results and how close they were to the accepted value. In this experiment, standardized NaOH solution with a given concentration of 0.09887 M is being used as the titrant to titrate acetic acid in Vinegar and citric acid in White Gatorade. The molarity of the acetic acid in Vinegar was an average of 0.5845 M and had an average % M/V value of 5.01 %. The molarity of the citric acid in White Gatorade had an average of 0.00953 M and had an average % M/V value of 0.183 %. The reliability of the results for acetic acid was very close to the accepted value of 5%. All values in the table are around the 5% range. The reliability of the results for citric acid was not the best before the accepted value is around 2.98% and our M/V values are much smaller than the accepted.

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