Acetic Acid in Vineger

CHE 131 Spring 2008 Experiment 4 - Determination of acetic inflamed-hot in vinegar Preliminary Reading: Chang, 9th ed., section 4.7, pp. 150-153 Introduction: The sense datum component of vinegar (besides wet) is acetic demigod, HC2H3O2, a weak demigod. In this experiment you will determine the concentration of acetic acid in a vinegar sample by titrating the acetic acid with the strong base sodium hydroxide, NaOH. The stoichiometry of the neutralization response is as follows: Molecular: Net Ionic: Neutralization: HC2H3O2(aq) + NaOH(aq) ? NaC2H3O2(aq) + water HC2H3O2(aq) + OH¯ (aq) ? C2H3O2+ (aq) + H2O H+(aq) + OH¯(aq) ? H2O(aq) (1) (2) (3) Definition: The end point (also recognize as the equivalence point) of a titration occurs when the initial takings of moles of H+ from the acid has been exactly neutralized by an equal matter of moles of OH¯ ion from the sodium hydroxide: moles H+ = moles OH¯ (4) The only species present at the end point ar the produ cts, sodium acetate and water. For reasons that are beyond the scope of the material covered so withdraw (but which will be covered in CHE 132), the solution is historical slightly basic at the end point of a weak acid-strong base titration. Consequently, an indicator must be select which transfers food color when the solution changes from acidic to basic.

Either phenolphthalein (colorless in acid, red in base, also used as the alert part in Ex-Lax?) or thymol game (yellow in acid, blue in base) may be used. Both indicators change color when the solution becomes very slightly basic Equipment: 25-mL pipette, 50-mL burette, 100-mL gradatory cylinder, 3 250-mL Erlenmeyer flasks, t hree 150-mL or 250-mL beakers, burette funne! l, 250-mL volumetric flask, wash up bottle, pipette bulb, eyedropper or Pasteur pipette with bulb, burette stand. You will be on the job(p) by yourself. Experimental: Obtain about 35 mL of vinegar in a clean, dry beaker and disgrace the credit or code number. This sample must be diluted before titration. Rinse a clean...If you want to institute a full essay, order it on our website: OrderEssay.net

If you want to get a full information about our service, visit our page: write my essay