observations of vinegar in chromatography
Answers
Explanation:
Theory
In the analysis that follows the force of one brand of vinegar will be measured via titration. The acetic acid is neutralized through a standardized sodium hydroxide solution as shown in the subsequent equation:
HC3H3O2(aq) + NaOHaq 1346_aro.jpg NaC2H3O2(aq) + H2Ol
Any vinegar sample might be utilized, but colorless vinegar is favored since it provides less interference through the examination of the indicator endpoint color change.
As the concentration of the vinegar solution is much higher than the concentration of our standardized sodium hydroxide solution, the original vinegar solution is diluted ten times prior to the titration. This dilution factor must be taken into account when calculating the concentration of the original vinegar solution
Procedure
1. Clean and dry the following material:
a. 500 mL plastic bottle.
b. 100 mL beaker.
2. Clean and rinse the following glassware with distilled water
a. 25.00 ml volumetric pipet.
b. 250.0 mL volumetric flask
c. 250 mL Erlenmeyer flask
d. 50 mL Buret
3. Measure exactly 25.00 mL of vinegar into a clean 250.0 mL volumetric flask.
As we know that be sure to utilize a dry beaker to transfer the vinegar.
Don't put any utilized vinegar back in the vinegar supply.
Be sure to rinse our pipette through vinegar prior to using it.
4. Dilute the vinegar with deionized water to the mark on the volumetric flask.
5. Stopper the flask and mix the solution well. (Invert the solution slowly for at least 10 times to completely mix the contents).
6. Transfer the dilute vinegar solution to a clean and dry 500 mL plastic bottle and label it with both the contents and your name.
7. Immediately wash your volumetric flask with plenty of tap water and several portions of deionized water. Let the flask dry at room temperature.
8. Pour about 50 mL of the dilute vinegar solution in your 100 mL beaker
9. Rinse your 25.00 mL volumetric pipet. Several times with portions of diluted vinegar from your beaker. Be careful not accidentally add any water to the diluted vinegar solution in the beaker.
10. Carefully pipet 25.00 mL of diluted vinegar solution into the 250 mL Erlenmeyer flask.
11. Add about 50 mL of deionized water to the Erlenmeyer flask.
12. Add 2 drops of phenolphthalein indicator solution and swirl the flask to thoroughly mix the solution.
13. Rinse your 50 mL buret several times with a few milliliters of your standardized sodium hydroxide solution.
14. Fill the buret with your standardized sodium hydroxide solution.
a. Make sure that the tip does not have any air bubbles.
b. Record the volume or the buret to the nearest 0.01 mL.
15. Titrate the acid sample to a faint pink end point.
16. Record the final volume of the buret to the nearest 0.01 mL.
17. Repeat the titration procedure described above for at least two more trials. The number of trials run depends on:
a. How much standardized sodium hydroxide solution you have available
b. The precision of your data.
Calculations
Moles of base = (Molarity of base)*(Liters of base)
Moles of acid (diluted vinegar) = Moles of base
Molarity of diluted vinegar = Moles of acid (diluted vinegar)/liters of acid (diluted vinegar)
The molarity of the original vinegar solution can be found by keeping in mind that the vinegar has been diluted ten times (from 25.00 mL to 250.0 mL) to obtain the diluted vinegar, whose molarity has been determined via titration through standardized NaOH.
Grams of HC2H3O2/Grams of vinegar = mol HC2H3O2/ L of vinegar * gHC2H3O2/mol HC2H3O2 * L vinegar / mL vinegar * mL vinegar /g vinegar
Density of vinegar = 1.0052g/mL
%weight HC2H3O2/weight vinegar = Grams of HC2H3O2/Grams of vinegar *100