Instructions 1. Re-read experiment 10 in your lab manual. 2. Read the following
ID: 879096 • Letter: I
Question
Instructions 1. Re-read experiment 10 in your lab manual. 2. Read the following scenario. 3. Using the data given in the scenario and the attached titration curve, complete and show any 4. Using the data and results for the scenario, identify the unknown acid from the table given on 5. On a separate sheet of paper, neatly and legibly write a conclusion paragraph that identifies necessary calculations in the space provided on the back of this sheet the back of this sheet. your unknown acid and clearly explains how you used your data and results to identify your how you excluded other possible compounds. It should not include calculations and it should not include lab procedures. Remember that a well-supported conclusion should compound. This paragraph should repeat important results/data for your unknown and discuss include the following .An introductory sentence that explains what you were trying to accomplish and how you achieved it. One or two sentences that describe how one data point for your unknown was used to narrow down the list of possible acids. These sentences should give the experimental value for the unknown as well as the names and accepted values for the possible acids that have made it to the-short list" of compounds to consider. You may report 96 differences if you choose to do so, but it is not mandatory in most cases. One or two sentences that describe how you used each subsequent experimental value for your unknown to identify it. You should report the value and describe how it compares to the accepted values for the possible acids from your "short list." Make sure you give those accepted values. You may report 96 differences if you choose to do so, but it is not mandatory in most cases. You should always use and discuss all relevant experimental data to which you have . access in your conclusion. .A conclusion sentence that clearly identifies your unknown. 6. I should be able to read this paragraph without looking at any other part of the assignment and be convinced that your conclusion is correct Scenario: A student titrated a 0.576 g sample of an unknown acid using 0.100 M NaOH. The following titration curve was generated using data from the titration. Using this information, i the unknown acid from the table of possible unknown acids. (Note: This acid is NOT necessarily the same as the one you used in experiment 10.)Explanation / Answer
Given acid is acetic acid
We calculate moles of acid from moles of base
Graph shows for monoprotic acid so
At equivalence moles base = moles of acid
Lets calculate mole of base
From graph volume of base = 60 mL = 0.060 L
Molarity of base = .100 m
Mol base= Molarity * volume of base in L
= 0.100 * 0.060 L = 0.006 mol
Mole of acid = 0.006 mol
Molar mass of acid = mass of acid in g/ number of mol
= 0.576 g / 0.006 mol
= 96 g per mol
Molar mass of this unknown acid is experimental and this is very close to molar mass
Of chloroacetic acid
Given acid is chloroacetic acid
We calculate volume of acid
Number of moles = Molarity * volume in L
At equivalence point volume is 60 so at half equivalence point volume of base is30
And at this pH of acid = pka
And if we look at the graphs then we get pH around 2.85 and so it is confirmed that
Above given unknown acid is chloroacetic acid