Question:What is the molar concentration of acetic acid in a sample of vinegar?Prediction:The manufacture of claims on the label that the vinegar contains 5.0% acetic acid, which translates into a 0.87 mol/L concentration of acetic acid. The concentration of acetic acid in the vinegar sample should be the same.Purpose:If we add acid solution to basic solution to produce water and salt this activity is called titration. It involves carefully adding one solution to another until chemically equivalent amounts react. Vinegar is a solution of a weak acid in water. This acid will react with the base sodium hydroxide in a 1:1 molar ratio. I ...view middle of the document...
NaOH is corrosive to flesh and can cause blindness. Wash up spills immediately using large amounts of water. Rinse your hands under running water if you come in contact with the NaOH solution. Wash your hands upon completion of the lab.Materials:Lab apron eye protectionNaOH(aq) vinegarPhenolphthalein wash bottle of pure waterTwo 100mL or 150mL 250mL beaker100mL volumetric flask with stopper 50mL buret10mL volumetric pipet pipet bulbring stand buret clampstirring rod small funneltwo 250mL Erlenmeyer flasks meniscus finderProcedure:1. 10mL of vinegar was obtained in a clean, dry 100mL beaker.2. One 10.00mL portion was pipeted into a clean 100mL volumetric flask and dilute to the mark.3. The mixture was mixed by stopper and inverts it.4. 50mL of NaOH(aq) was obtained in a clean, dry labeled 100mL beaker.5. The buret was set up with NaOH(aq) following the accepted procedure for rinsing and cleaning the air bubbe.6. 10.00mL of diluted vinegar was pipeted into a clean Erlenmeyer flask.7. 2 drops of phenolphthalein indicator was added.8. The initial buret reading was recorded to the nearest 0.1mL.9. The sample with NaOH(aq) was titrate until a single drop produces a permanent change to pink.10. the final burner reading was recorded to the nearest 0.1mL11. Steps 6 to 10 were repeated until three concerted results are obtained.Observations:Titration of 10mL of HC2H3O2 with 0.99 mol/L of NaOH(aq)Trial 1 2 3Final buret reading (mL)Initial buret reading (mL)Value of NaOH(aq) added
