Chemistry lab report, chemistry homework help

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7nef

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hello,

Read the information on the first picture and follow it.

Note: picture 2 question 2 only do one sample ( trail one ) and then calculate it ( in picture number 3 )

Note 2: for picture number 2 question 2 use realistic numbers to do i

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Doing the Trial Titration 1. Pipet 10.0 mL of vinegar into a clean 125-mL Erlenmeyer flask. Add about 20 mL of distilled water from a clean graduated cylinder. Add 2 drops of phenolphthalein solution. CAUTION: Never use your mouth to draw liquid into the pipet. Use a rubber suction bulb. Na oH 12. Record the molarity of the NaOH solution and the initial buret reading. 3. Place the flask under the buret with the capillary tip inside the mouth of the flask. Place a piece of white paper under the flask, white hase 4. Add the NaOH solution to the flask in increments of about 1 mL while swirling. Note the color of the solution after each addition. 5. This trial titration is complete when an addition of about 1 mL causes the color to change from colorless to any shade of pink. 6. Record the buret reading. Subtract the initial reading from this reading to obtain the volume required for the approximate end point. Doing the Exact Titrations 1. Repeat Steps 1, 2, and 3 of the procedure used for the trial titration. 2. Subtract 1 mL from the volume found in the trial titration. Rapidly add the resulting volume to the flask from the buret. 3. Rinse the walls of the flask with distilled water from a plastic wash bottle. 4. Continue the titration on a drop-by-drop basis. Swirl the flask rapidly after each drop. The end point is the first permanent, barely visible pink color. Finding the true end point requires patience and skill. Absolutely no skill is required to miss the end point and achieve a very deep pink color. If you are unsure about the end point, record the buret reading before you add the next drop. 5. Repeat the procedure with a second sample of vinegar. 6. If the volumes at the end points of these two exact titrations differ by more than 0.15 mL (about 3 drops), repeat the titrations with additional samples of vinegar until two consecutive results have this precision. 7. Calculate and record the molarity of the vinegar from each of the two titrations. Does each molarity have the correct number of significant figures? Obtain the mean molarity. 4C How Much Acetic Acid Is in Vinegar? NAME SECTION DATE Results Molarity of the NaOH solution: 1. Trial titration Final buret reading (mL): Initial buret reading (mL): Volume of NaOH solution (mL): 2. Exact titrations Sample No. 1 2 3 4 Final buret reading (mL) Initial buret reading (mL) ID Volume of NaOH solution (mL) Concentration of HC,H,O2 (M) Mean concentration (M) 150 / Experiment 4C Calculations: How Much Acetic Acid Is in Vinegar? / 151 Questions 1. The manufacturer of the vinegar used in this experiment claims that the vinegar contains 5% acetic acid by weight. Use your results and a density of 1.0 g/mL to investigate this claim. 152 | Experiment 4C 2. Redo the numerical problem in the Prelaboratory Assignment, substituting H2SO, for HCI.
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Explanation & Answer

attached is my complete lab report & solution

Procedure Summary:
1. Trial titration:






10 mL of HC2H3O2 were pipetted into a flask, and 20 mL of distilling water was added there.
Also, few drops of phenolphthalein were added.
The molarity of the NaOH solution records to be 0.3 M, and the initial buret reading is
recorded to be 50 mL.
The NaOH solution was added to the flask in increments of about 1 mL during swirling, and
this trial titration is complete when the addition of about 1 mL causes the color to change
from colorless to pink.
The final buret reading was recorded, and it was subtracted from the initial reading to
obtain the volume required for the approximate endpoint.

2. Extract titrations:





The first three steps of the procedure used for the trial titration were repeated.
1 mL from the volume found in the trial titration was subtracted, and the resulting volume
was rapidly added from the buret to the flask.
Now, the titratio...


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