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Lab report project 3: volumetric determination of acetic acid in vinegar-i
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Vinegar is liquid with main component acetic acid (also known as ethanoic acid) and as well as some other chemicals compound. The estimation of the acetic acid concentration in a sample of vinegar was determined based on the stoichiometric reaction between sodium hydroxide (NaOH) and acetic acid that form sodium acetate (CH3COONa) and water (H2O) as follow. CH3COOH (aq) + NaOH (aq) CH3COONa (aq) + H2O (l) However, the method of volumetric analysis is highly dependent on a pure standard which the amount of substance present is accurately known. Prior to estimation of the acetic acid, sodium hydroxide (NaOH) was used as the standard solution. Thus, the concentration of the sodium hydroxide (NaOH) was first determined because sodium …show more content…
An acid-base indicator is a substance that undergoes a distinct colour change at or near the equivalence point. The point in the titration at which the colour change occurs is called as end point. Obviously, the titration will be accurate only if the end point and the equivalence point coincide fairly closely. For this reason, an acid-base indicator used in this acid-base titration must be selected carefully in order to obtain an accurate result. Thus, the acid-base indicator used in this experiment is the phenolphthalein. Besides, phenolphthalein is also a suitable indicator for titration between a strong base and a weak acid. Phenolphthalein is colourless in an acid solution but pink in base solution. Phenolphthalein was added into both original oxalic acid (C2H2O4) and acetic acid (CH3COO) solution before the acid-base titration was carried out. Phenolphthalein is a weak acid and is represent as Hln in the following chemical …show more content…
In acid-base chemistry, the solution concentration is expressed in normality (N or CN). Normality is defined as number of equivalent weights of solute that dissolved in per liter of solution. As a practical matter, normality closely resembles with molarity or moles per liter. Therefore, scientific textbooks typically define the normality of an acid or base as “equivalents per liter”. Normality is used in place of molarity as mostly 1 mole of acid does not neutralize with 1 mole of base. Most of the chemists prefer to express the concentration of acids and bases in normality as to have a one-to-one relationship between acids and bases. In monoprotic acid and monoprotic base such hydrochloric acid (HCl), hydrogen bromide acid (HBr), sodium hydroxide (NaOH) and potassium hydroxide (KOH), its normality is equal to the molarity (N=M). This is because monoprotic acid and base have 1 equivalent hydrogen ion (H+) and hydroxide ion (OH-) respectively per liter of solution. Meanwhile, for diprotic acid and base such as calcium hydroxide, Ca(OH)2 and sulphuric acid, H2SO4, its normality is equal to twice the molarity (N=2M). This is due to diprotic acid and base have 2 equivalent hydrogen ion (H+) and hydroxide ion (OH-) respectively per liter of
...ost likely to be battery acid. If it is water, it has a Ph level of around 7. For vinegar, the Ph level is approximately 2.4 - 3.4. Thus, once testing the liquid compare it with the Ph levels above to discover the mystery solution.
In the first section, the Synthesis of Aspirin, salicylic acid was weight to be 3.029 grams using mass by difference since it was weighed on a 150 milliliter beaker. 9.23 milliliters of the acetic anhydride and 14 drops of 85 percent phosphoric acid were added to this beaker. A Bunsen burner provided by the laboratory was then used to boil the just mixed combination by producing a flame underneath the positioned beaker on top, and then allowed to cool for several minutes after the Bunsen burner flame was terminated. Two quantities of distilled water were then added to this mixture to make it cool even further, which were 41 drops and 30 milliliters. After cooling for some time, this beaker was placed into an ice bath in order to start the crystallization process. A glass rod was used to scratch around the bottom and the sides to catch all of the crystallized Aspirin that was being formed during this whole process. Then, by using a Buchner funnel and filter paper, which was placed on top of the flask connected to a water aspirator with rubber tubing, the excess liquid was removed from the just scraped Aspirin crystals when the Aspirin was placed on the filter paper. Using a medicine dropper, the Aspirin crystals on the filter paper were washed with distilled water just so that any non-pure substances were removed from the crude product. When these crystals were then ultimately dry, they were placed on a watch glass and put into an oven for 30 minutes. Then they were weighed by mass by difference to yield 2.4667 grams of crude s...
ranging from 50 cm³ of acid and no water, to 12.5 cm³ of acid and 37.5
Another common myth is teeth whitening. “Acid, whether it be in lemons or soda or apple cider vinegar, destroys your protective layer of enamel permanently.”, Chodosh reminds us that acid can be severely damaging to our oral health. She insists that do not ever try this, thus shooting down another myth. She continues to point out flaws in beliefs shooting down sore throats, warts and pimples. Chodosh saves the most important for last, rejecting how in any way, that apple cider vinegar could cleanse a vagina in any way. Chodosh comments, “DO NOT PUT VINEGAR IN OR ANYWHERE NEAR YOUR VAGINA OR VULVA.”, she backs this up with how the acid will affect the ph level and there could be serious consequences. With her rant coming to an end, she proposes the one thing that apple cider vinegar could possibly help with. Dandruff. She eagerly analyzes that the anti-microbial features present in the liquid could help get rid of some fungus and dead skin hanging around on the scalp. However, insisting that this is not a cure and that you should seek a dermatologist if the issue
Fill each cup with 50 mL of the following liquids (using the graduated cylinder to measure):
The most effective method for testing the percentage of NaHCO3 and Na2CO3 in a mixture was determined to be Test 3: Pressure Analysis. While it was not as effective as Test 1: Solution Conductivity when adhering to principles of Green Chemistry, but Test 3 provided the most accurate results. The reactions between Na2CO3 or NaHCO3 and Acetic Acid produced Sodium Acetate, Water and Carbon Dioxide. While it did produce CO2 and Sodium Acetate which are waste products, they are considered non-hazardous being the side products of the common baking soda and vinegar reaction. Test 2, Thermal Decomposition, was determined to ineffective. The waste products of Test 2 were in greater number, 2 grams of solid Na2CO3 and NaHCO3 mixture had to be disposed, and there was a great waste in heat energy from the hot plate. The hot plate was left on
The I acid I vinegar I is I a I liquid I that I is I made I up I of I mainly I acetic I acid I and water. I Vinegar I is I generally I used I as I a I cooking I ingredient.
Second description of acids and bases is found by Danish chemist J.N. Bronsted and English chemist in T.N LOWRY in 1923. According to them matter that gives protons are acid and matter that receive proton is base. With this description matters that aren’t thought to be an acid or base is now classified as an acid or a base. For example Boron trifluoride is act as an acid an...
The purpose of this experiment was to learn and preform an acid-base extraction technique to separate organic compounds successfully and obtaining amounts of each component in the mixture. In this experiment, the separation will be done by separatory funnel preforming on two liquids that are immiscible from two layers when added together. The individual components of Phensuprin (Acetylsalicylic acid, Acetanilide, and Sucrose as a filler) was separated based upon their solubility and reactivity, and the amount of each component in the mixture was obtained. Also, the purity of each component will be determined by the melting point of the component.
The same procedure was done using 10ml of CV and 20ml of sodium hydroxide, both separately diluted to 50ml and added in a large beaker. The absorbance was recorded. In the last trial, 10ml of CV, 10ml of NaOH were diluted to 50ml. Before adding the two mixtures, 1ml of soap was added to the NaOH solution and then poured into a large beaker, along with the CV. Absorbance was recorded and the materials
We noticed that the white vinegar was more polluted by the 5th day. The white vinegar was the most polluted out of all three bottles. We noticed by the 8th day the two test bottles have gained almost an unbearable odor, and the anacharis plant started to decompose in the white vinegar column, which most likely caused the growth of another living organism, mold! So, there is more evidence that the solutions affected the biotic and abiotic components of the 2 test
Analysis of Aspirin Tablets Aim --- To discover the percentage of acetylsalicylic acid in a sample of aspirin tablets. ----------------------------------------------------------------- In order to do this, the amount of moles that react with the sodium hydroxide must be known. This is achieved by using the method of back titration.
When benzoic acid paired with 1.0 M NaOH, it was observed that both compounds were soluble. Upon the addition of 6.0 M HCl into this solution, benzoic acid became insoluble. Benzoic acid was also insoluble in 1.0 M HCl. Ethyl 4-aminobenzoate was found to be insoluble in 1.0 M NaOH and soluble in 1.0 M HCl. But then, after adding 6.0 M NaOH into the test tube C (mixture of ethyl 4-aminobenzoate and 1.0 M HCl), a white powdery solid (undissolved compound) was formed. These demonstrate that both the acid and base became more soluble when they were ionized and less soluble when they were
According to the conductometric titration, the concentration of Ba(OH)2 (aq) was 0.196 M. Calculations based on gravimetric analysis revealed a concentration of 0.0669 M. Evidently, there is a high degree of imprecision between the values determined by each technique. It appears however that the gravimetric analysis was more accurate. The standard deviation for BaSO4 mass was 0.035 and the confidence interval was ±0.0256 g. This illustrates that there is 90% certainty that the actual mass of the BaSO4 precipitate was within 0.0256 g of the calculated mean (0.156 g). It should be noted that an outlier (1.45 g precipitate) was removed from the gravimetric analysis calculations due to being 9.29 times greater than the average. The standard deviation for end point volume – the basis of calculations for the conductometric titration – was 6.616. The confidence interval was ±5.443 mL. The much larger confidence interval for end point volume illustrates a higher degree of uncertainty regarding the precision of this measurement. For this reason, it appears that gravimetric analyses are more suitable for determining saturated solution concentration. This has importance in research where the solubility product (Ksp) needs to be determined or when predictions need to made regarding whether a precipitate will form. One of the principle reasons why conductometric titration
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).