1 answer

1. Use the data given to calculate the following parts: a. Using your data for the...

Question:

1. Use the data given to calculate the following parts:

Suggested Setup for Lab Notebook (All lab data goes in the notebook; do not record lab data here) Molarity of NaOH (determine

a. Using your data for the value for VEP1, calculate the molarity of H3PO4 at the 1st equivalence point, EP1. Show work clearly, with units and correct significant figures.

b. Using your data for the value for VEP2, calculate the molarity of H3PO4 at the 2nd equivalence point, EP2. Show work clearly, with units and correct significant figures.

c. Calculate the percent error between these two molarity values, % error = 100 x |value1 – value2| / (average of value 1 and value 2). Show work clearly with correct significant figures.

d. Tabulate your average values of pKa1 and pKa2, and the accepted values. Calculate the percent error of pKa1 and pKa2. Show work clearly with correct significant figures.

e. Your unknown acid is oxalic acid (H2C2O4*2 H2O, pKa1 = 1.27, pKa2 = 4.27), or citraconic acid (C5H6O4, pKa1 = 2.29. pKa2 = 6.15), or maleic acid (C4H4O4, pKa1 = 1.92, pKa2 = 6.09). ——— These three acids are diprotic.

f. Calculate the molar mass of your unknown acid two different ways:
i. Use the average mass from trials 1 and 2, and the average volume of the first equivalence point
ii. Use the average mass from trials 1 and 2, and the average volume of the second equivalence point. Show work clearly, with units and correct significant figures.
iii. Using the average mass at the 2nd equivalence point, and your average values of pKa1 and pKa2, identify your unknown acid. Explain your answer.

Suggested Setup for Lab Notebook (All lab data goes in the notebook; do not record lab data here) Molarity of NaOH (determined in Experiment 8) 0.2202 PART A: Titration of Phosphoric Acid TRIAL 1 TRIAL 2 Volume of phosphoric acid used 15.00 mL 15.00 mL Volume at equivalence point NaOH 6.87 mL 13.73 mL 6.80 mL 13.60 mL pH at half the 1s equivalence point 1.72 1.84 pH at the point halfway between the 19 and 2nd equivalence points 7.41 7.16 Average value of pka1 Average value of pKaz PART B: Titration of Unknown Acid Code of Acid B TRIAL 1 TRIAL 2 Mass of acid used 0.1415 g 0.1631 a Volume at equivalence points NaOH 5.13 mL 10.25 mL 6.63 mL 13.25 ml pH at half the 1st equivalence point 1.71 1.76 pH at the point halfway between the 1st and 2nd equivalence points 6.44 6.25 Average value of pka Average value of pKa2 7

Answers

a) The molarity of the acid is calculated, with respect to its first equivalence point:

Ca = Cb * Vb / Va = 0.2202 M * 6.87 mL / 15 mL = 0.1009 M

Trial 2: 0.0998 M

b) The molarity of the acid is calculated with respect to its second equivalence point:

Ca = 0.2202 M * 13.73 mL / 15 mL * 2 = 0.1008 M

Trial 2: 0.0998 M

c) The error is calculated:

% error = 100 * (0.1009 - 0.1008) / (0.1009 + 0.1008) / 2 = 0.1%

Trial 2: 0%

d) The pKa errors are calculated:

% error pKa1 = (1.78 - 2.12) * 100 / 2.12 = 16%

% error pKa2 = (7.21 - 7.29) * 100 / 7.21 = 1.1%

.

Similar Solved Questions

1 answer
Can you please answer all these questions. thank you 12:15 NO. + Expert Q&A 0 +...
can you please answer all these questions. thank you 12:15 NO. + Expert Q&A 0 + 1, what are the requirements for corporations to file a consolidated tax return? 2, what if any benefits are there to filling a consolidated tax return? 3, can a non U.S. corporation join in the filing of a consolida...
1 answer
Please give a good explanation. These two wave pulse travel along the same stretched string, one...
Please give a good explanation. These two wave pulse travel along the same stretched string, one after the other (assume tension is identical). Which is true? am doc > B. VB VA ay D. Not enough information to tell....
1 answer
8. Convert the following NFA to DFA a,
8. Convert the following NFA to DFA a,...
1 answer
A key difference between a replacement project analysis and an expansion project analysis is that the...
A key difference between a replacement project analysis and an expansion project analysis is that the net present value (NPV) technique that is used to evaluate capital budgeting projects should only be used to evaluate expansion projects, whereas either the NPV technique or the internal rate of ret...
1 answer
8. ( 10 points) Show the B-trees of order four resulted from loading the following sets...
8. ( 10 points) Show the B-trees of order four resulted from loading the following sets of keys (each letter is a key) in order a.CGJX b. CGJXNSUOAEBHI c.CGJXNSUOAEBHIF d. CGJXNSUOAEBHIFKLQRTVUW z...
1 answer
5. (4x 4-16 pts) Fig. 1 Fig. 2 () A double slit apparatus withd -0.01 mm...
5. (4x 4-16 pts) Fig. 1 Fig. 2 () A double slit apparatus withd -0.01 mm is illuminated by light (Fig 1). The position of the first maximu m on the screen 2 m away is measured to be 10cm away from the (i) In an ensuing flood, water (n 1.33) fills the laboratory and the apparatus. Does the (ili) Afte...
1 answer
Your answer is incorrect. Try again Bonita Inc. began operations in January 2018 and reported the...
Your answer is incorrect. Try again Bonita Inc. began operations in January 2018 and reported the following results for each of its 3 years of op 2018 $252,000 net loss 2019 $39,000 net loss 2020 $868,000 net income At December 31, 2020, Bonita Inc. capital accounts were as follows. 400.000 8 cumula...
1 answer
Delaware Corp. prepared a master budget that included $12,090 for direct materials, $28,300 for direct labor,...
Delaware Corp. prepared a master budget that included $12,090 for direct materials, $28,300 for direct labor, $15,000 for variable overhead, and $39,200 for fixed overhead. Delaware Corp. planned to sell 4,030 units during the period, but actually sold 4,380 units. What would Delaware’s direct...
1 answer
EyeGuard Equipment Inc. (EEI) manufactures protective eyewear for use in commercial and home applications. The product...
EyeGuard Equipment Inc. (EEI) manufactures protective eyewear for use in commercial and home applications. The product is also used by hunters, home woodworking hobbyists, and in other applications. The firm has two main product lines—the highest-quality product is called Safe-T, and a low-cos...
1 answer
Question 4 (a) In the explanation of labor matching models, I assumed without explanation that firms...
Question 4 (a) In the explanation of labor matching models, I assumed without explanation that firms will always hire two adjacent workers. Why does this make sense? Explain briefly. [Draw out a line with three workers. Why wouldn’t the firm want to hire the two workers who are non-adjacent?] ...
1 answer
Balance the following redox reaction in basic solution. You will need to show all work including...
Balance the following redox reaction in basic solution. You will need to show all work including half-reactions, balancing of O, H, electrons and the final balanced reaction. Cr(OH)3(s) + ClO3−(aq) --- CrO42−(aq) + Cl−(aq)  ...
1 answer
Question : The average height of members of the high school basketball team is six feet, three inches
1. Question : The average height of members of the high school basketball team is six feet, three inches. Jerry is on the high school basketball team, so Jerry must be taller than six feet. The argument above is flawed because it confuses: Student Answer: 4CORRECT an average for the individuals that...
1 answer
Installation of stairways of wayang Juestion Stellar Stairs Co. designs and builds factory made premium wooden...
installation of stairways of wayang Juestion Stellar Stairs Co. designs and builds factory made premium wooden stairways for homes. The manufactured stay components (spindles, risers, hangers, handrails) per lengths and widths. All are made of white oak wood. The company's budgeted manufacturing...
1 answer
What do you believe is the most important aspect of teaching during the prenatal and postpartum...
What do you believe is the most important aspect of teaching during the prenatal and postpartum phases of pregnancy? Why?...
1 answer
Please make sure to also draw mohrs circle For the un-symmetric C-section shown below 1- Locate the centroid "C" 2- Detemine the principal axes and moments of inertia about the centroid....
please make sure to also draw mohrs circle For the un-symmetric C-section shown below 1- Locate the centroid "C" 2- Detemine the principal axes and moments of inertia about the centroid. 3- Detemine the moments and product of Inertia with respect to the u-v axes using Mohr's circle ye 0...
1 answer
(a) Suppose a Toy factory makes 4,000 are Blue and rest are Black. You es 20,000...
(a) Suppose a Toy factory makes 4,000 are Blue and rest are Black. You es 20,000 toys on a day. Out of which 10,000 are Red, o ility that the teot tre Black. You begin picking Toys in random, whiat is the probability that the 10th toy you pick will be the third Black toy...
1 answer
Task 1: Explain, with the help of diagrams where appropriate the natural frequency of vibration in...
Task 1: Explain, with the help of diagrams where appropriate the natural frequency of vibration in a mass-spring systerm...
1 answer
5. Sketch the region enclosed by the curves y = (x – 2)2 and y =...
5. Sketch the region enclosed by the curves y = (x – 2)2 and y = x then find its area using the appropriate definite integral....