Acid-Base Titration I. Abstract The purpose of the laboratory experiment was to determine equivalence points, pKa, and pKb points for a strong acid, HCl, titrated with a strong base, NaOH using a drop by drop approach in order to determine completely accurate data. The data for this laboratory experiment is as follows. Using a concentration of .1 NaOH we had the largest NaOH volume before the largest pH increase at 6.38ml. For the largest NaOH volume after the largest pH increases we used 6.73ml of base. The volume of NaOH used at the equivalence point, pH 7, was 6.575ml. The moles of NaOH used at this point were .0006575mols. Using stochiometry, the moles of HCl were also .0006575 at the equivalence point. Finally, our concentration of HCl was calculated out to be .06575 Molarity. V. Data a. General Data Concentration of NaOH .1M NaOH volume added before the largest pH increase. 6.38mL NaOH volume added after the largest pH increase. 6.73mL Volume of NaOH at equivalence point. 6.575mL Moles NaOH .0006575mol Moles HCl .0006575mol Concentration of HCl .06575M b. Computer Data Graph: See Attached c. 23Drops From Buret = 1mL VI. Mathematics a. Stoichiometry Molarity=Moles/Volume(L) .5M NaOH=X/.00185L NaOH X=.00925 mol NaOH .00925mol NaOH * 1mol HCl/1mol NaOH=.00925mol HCl .00925mol HCl/.005L = .185M HCl b. Drop Calculations Vol/Number of Drops. 1mL/23Drops = .034mL/drop VII. Conclusion Unlike other labs, this lab allowed for the most precise titration results possible. The reason for this is that separate drops were entered one at a time and their volume was computed in order to add to the total. However, due to the fact of adding drops one at a time, time became an issue while completing the experiment. One titration took nearly 30minutes in order to complete flawlessly. On the other hand, the results achieved show how slow and steady wins the race.
We then took 1ml of the 0.1% solution from test tube 2 using the glucose pipette and added it to test tube 3, we then used the H2O pipette and added 9ml of H2O into test tube 3 creating 10ml of 0.01% solution.
taken into account. It is also best to make sure you are working in a
* pH of Solution: Water has pH of 7 at 25°C. As the pH decreases,
10cm3 of 1 molar solution. I will use 3 of each solution to ensure that
how much base was needed in (ml). Once we titrated all the bottles we then
0.091 moles, giving a yield of 76% or based on 10.5 cm3, a yield of
The equation shows how 1 mol of Na2CO3 reacts with 1 mol of H2SO4, so
Moles Volume HCl Volume Water 2 M 10 cm 3 0 cm 3 1.5 M 7.5 cm 3 2.5 cm 3 1 M 5 cm 3 5 cm 3 0.5 M 2.5 cm 3 7.5 cm 3
Determining the Relative Atomic Mass of Lithium An experiment has been carried out to determine the relative atomic mass of Lithium by using two different types of methods The first method that was carried out was to determine the volume of Hydrogen produced. In this experiment a fixed amount of Lithium was used, in my case it was 0.11g. At the end of this experiment, the volume of Hydrogen gas I collected was 185cm³. Then using the solution of lithium hydroxide made from experiment one, I used it in the titrating experiment, to find out the total volume of Hydrochloric acid used to titrate the lithium hydroxide. RESULTS TABLE Experiment Initial Volume ( cm³) Final Volume ( cm³) Total volume Of HCl used ( cm³) Rough 0.2 30.3 30.1 1 6.3 35.8 29.5 2 2.7 32.0 29.3 Average 29.6 CONCLUSION Method 1 [IMAGE]2Li (s) + 2H20(l) LiOH(aq) + H2(g) Number of moles of Hydrogen. Volume of hydrogen gas was 185 cm³. Weight of Lithium was 0.11g. N = __V__ _185_ = 0.0077 MOLES 24000 24000 Number of moles of Lithium.
As more NaOH is added, the pH will become more basic as H2C2O4 .2H2O has been completely neutralized and now an excess of OH- ions are present in the solution.12
Acid-Base balance is the state of equilibrium between proton donors and proton acceptors in the buffering system of the blood that is maintained at approximately pH 7.35 to 7.45 under normal conditions in arterial blood. It is important to regulate chemical balance or homeostasis of body fluids. Acidity or alkalinity has to be regulated. An acid is a substance that lets out hydrogen ions in solution. Strong acid like hydrochloric acid release all or nearly all their hydrogen ions and weak acids like carbonic acid release some hydrogen ions.
Titration is a technological process in which a solution, known as a titrant, is slowly and carefully added from a burrette into a fixed volume of another solution (known as the sample). In an acid-base titration an acid neutralizes a base or vice versa. This process is maintained untill the reaction between the titrant and the sample (acid and the base) is judged to be complete. The reaction is judged to be complete when the endpoint is reached. An endpoint in a titration analysis is referred to as the point at which no more titrant is added due to an observable colour change of an indicator. Indicators can be used to find an endpoint because they change colour when the pH of a solution changes and an endpoint in a titration is an empirical approximation of the equivalence point, which is the point of major pH change in the titration sample due to the fact that equal chemical amounts of reactants have been combined at that point. All indicators have a pH range, which is the range of pH values at which the colour of the indicator changes. Thus
The purpose of this experiment is to use our knowledge from previous experiments to determine the exact concentration of a 0.1M sodium hydroxide solution by titration (Lab Guide pg.141).
the left so that the concentration of H is more than Me and so the