Titration of a Strong Base with a Strong Acid Sec 215 Meshail AlMuhanna 201101736 Alaa AlGhamdi 201101033 Alaa AlMobarak 201101810 Fajer AlBoaynen 201100589

Objective: To determine the molarity of hydrochloric acid in the given sample. To learn lab skills to prepare and dilute standard solution and to find the strength of an acid or a basic solution.

Materials used: 50-ml burette. 5-ml volumetric pipette. 0.1M NaOH. Hydrochloric acid. Phenolphthalein indicator. Burette stand. Two 250ml Erlenmeyer flasks. Wash bottle filled with distilled water funnel.

Experimental procedure: Add 10 ml of hydrochloric acid in a flask. Add 3 to 4 drops of Phenolphthalein to the hydrochloric acid, the solution is currently clear (without color). add NaOH to the burette by a funnel and put on the burette stand. Record the starting reading of the burette.

Add small drops of the NaOH to the hydrochloric acid, and shake it to mix the solution.

While we are adding the drops of NaOH to the hydrochloric the solution’s color will turn pink and the pink color will disappear after we shake the solution. We keep adding drops of NaOH to the hydrochloric until the pink color stays and doesn’t disappear. When the solution stays as a pink color it means that the solution reached the equivalent point.

Record the ending point reading the burette. NaOH + HCl  NaCl + H2O Repeat all the steps one more time to get a second trail.  For the unknown sample we will repeat the same steps.

Calculation and result: The volume of NaOH = starting burette reading – end point reading The average of the volume = we add the volume of trail 1 and trail 1 divided by 2. The moles of NaOH = volume(L) x molarity of NaOH Moles of hydrochloric acid = moles of NaOH x 1 mole of hydrochloric acid/1 mole of NaOH. Molarity of hydrochloric acid = moles of HCl divided by volume of sample used.

Applications of Titration: Medical Uses Pharmacists use titration to achieve a desired mix of compound drugs. Doctors will often employ titration to determine the correct proportion of different medicines in an intravenous drip. Titration is also used to monitor blood glucose levels in patients with diabetes, as well as in pregnancy tests and other applications of urinalysis.

2. Food Industry Uses Titration can be used to define oils, fats and similar substances. Specific titration procedures exist to test free fatty acid content, unsaturated fatty acids and trace amounts of water. Titration is also used to determine the estimated chain length of fatty acids in a fat. Other uses of titration in the food industry include tests for the amount of salt or sugar, and the concentration of vitamin C or E, in a product. Titration is also used in wine and cheese production to test the product's readiness for consumption.

3. Aquarium Water Testing Titration is used to test the underwater environment in fresh water and marine aquariums. Properties such as water pH and concentration of ammonia, nitrates and nitrites are measured and then corrected to ensure the survival of marine life being kept in the aquarium.

Conclusion: This experiment has taught me the difference between a base and an acid, that the PH of an acid is less than 7 and the PH of a base is more than 7. It taught me that result of mixing a base and an acid is salt water. I also learned the titration method of determining the molarity of acid in a sample. The titration controls the reaction between the titrant which is the solution of known concentration, and the analyte which is the solution of unknown concentration. We learned how to use PH indicators, when we add a couple of drops of the solution to determine the PH of the solution we can see the difference of the solution color for example when we add the Phenolphthalein indicator to HCl the color will not change, but when we add it to NaOH the color of the solution will change into a pink color.