Standardization of Sodium Hydroxide Solution

We know that that the end point of the titration is reached when, after drop after careful drop of NaOH, the solution in the flask retains its pale pink color while swirling for about 30

2. To titrate a hydrochloric acid solution of “known” concentration with standardized 0.5M sodium hydroxide.

HCl, (moles of HCl to moles of NaOH) so the pH begins to increase slowly, this raises

solids and liquids that were in the solution. The centrifuge was able to do this

Here, the bicarbonate reacts with a proton(from excess acid in the stomach)to release carbon dioxide(H20 + co2).

This is the point of stoichiometric equivalence, meaning the number of mols of both substances are equal. The mols used in the known solution can be found by multiplying the molarity by the volume used in titration. The molarity of the unknown solution can be found by dividing the number of mols, which is equal to the number of mols titrated in the known solution, by the volume in liters of the unknown solution. Titrating in this lab works because the one H+ ion in the KHP and HCl consumes and neutralizes the one OH¬- ion found in the NaOH. Standardization involves titrating the same solution multiple times to obtain an average molarity of the solution from the many

Volumetric burette: This instrument was filled with the sodium hydroxide solution that would be gradually added to the vinegar solution. The burette was used instead of a measuring cylinder as it gives a finer volume

19. Stir the solution with a toothpick and observe any changes. Measure the pH of the new solution and record into Table 2.

To begin, three sets ofabout 0.3000g of KHP are weighed out on an analytical balance. Put the three sets of KHP into three separate, labeled flasks. All three sets of the KHP is then dissolved with approximately 50mL of deionized water. Next, a buret is used to start the actual titration. Buret is initially filled to 0.00mL mark with the NaOH solution, this is recorded as initial volume. Next, add 2-3 drops of phenolphthalein indicator into each of the three flasks containing KHP. A magnetic stir bar is then added to the first flask, and placed above a stir plate. Everything is positioned under the buret. Stirrer is put on medium speed and the titration can start. Slowly release the NaOH into the KHP flask. As the end point is reached, a pink color will be seen in the flask. When the lightest pink possible remains in the solution for more than 30 seconds titration is complete. The final volume is recorded, and the same steps are taken for the other two sets of KHP solution. Finally, blank titration is completed to determine deviation.

Its concentration was found through a quantitative and qualitative titration testing. Because HCl is acidic, a 1.07M NaOH solution was used to titrate an aqueous solution of HCl (the unknown solution). The PASCO program gave the final results shown in Figure 1. A typical titration curve can be described as starting at the initial pH of the solution, then some acid/base is added, until a sharp curve either up or down takes the pH past a neutral of 7, and towards the pH level of whatever the added acid’s/base’s pH is (Clark6). The stronger the acid or base being titrated, the faster the change occurs, which means a sharper slope of the titration graph. Also, it is important to note the equivalence point on this titration graph. At the equivalence point “the correct amount of standard solution must be added to fully react with the unknown concentration” (Xavier3). In Figure 1, this equivalence point is shown by where the sharpest slope occurs in the curve, which is seen at about a pH of 5.0

The process was then repeated for the second reaction but using 1.00-mL of a 6.00-M phosphoric acid solution and 4.00-mL of a 3.00-M sodium hydroxide solution.

By using acid-base titration, we determined the suitability of phenolphthalein and methyl red as acid base indicators. We found that the equivalence point of the titration of hydrochloric acid with sodium hydroxide was not within the ph range of phenolphthalein's color range. The titration of acetic acid with sodium hydroxide resulted in an equivalence point out of the range of methyl red. And the titration of ammonia with hydrochloric acid had an equivalence point that was also out of the range of phenolphthalein.. The methyl red indicator and the phenolphthalein indicator were unsuitable because their pH ranges for their color changes did not cover the equivalence points of the trials in which they were used. However, the

When it is almost neutralized, pour possible minimum amount of sodium hydroxide for a fair result.

The purpose of this lab was to use process titration to find concentration of an aqueous solution of Hcl(aq) , using KOH(aq) as the titrant.

An acid-base titration is the determination of the concentration of an acid or base by exactly neutralizing the acid/base with an acid or base of known concentration. This allows for quantitative analysis of the concentration of an unknown acid