why is it necessary to test the ph? EXTRME DETAIL PLEASE PROCEDURE To a six inch test tube was added thiamine hydrochloride (0.65 g), followed by water (2 mL). The mixture was gently shaken until homogeneous, and then ethanol (7.5 mL) was added. Finally, sodium hydroxide (10%, 1.5 mL) was added and the mixture was gently stirred to ensure complete mixing. Benzaldehyde (3.8 mL) was then added at room temperature in one portion with gentle stirring. The pH of the resulting reaction mixture was determined and adjusted to >10 by dropwise addition of 10% sodium hydroxide.

why is it necessary to test the ph? EXTRME DETAIL PLEASE PROCEDURE To a six inch test tube was added thiamine hydrochloride (0.65 g), followed by water (2 mL). The mixture was gently shaken until homogeneous, and then ethanol (7.5 mL) was added. Finally, sodium hydroxide (10%, 1.5 mL) was added and the mixture was gently stirred to ensure complete mixing. Benzaldehyde (3.8 mL) was then added at room temperature in one portion with gentle stirring. The pH of the resulting reaction mixture was determined and adjusted to >10 by dropwise addition of 10% sodium hydroxide.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter20: Applications Of Oxidation/reduction Titrations

Section: Chapter Questions

Problem 20.6QAP

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why is it necessary to test the ph? PROCEDURE To a six inch test tube was added thiamine hydrochloride (0.65 g), followed by water (2mL). The mixture was gently shaken until homogeneous, and then ethanol (7.5 mL)was added. Finally, sodium hydroxide (10%, 1.5 mL) was added and the mixture wasgently stirred to ensure complete mixing.Benzaldehyde (3.8 mL) was then added at room temperature in one portion with gentlestirring. The pH of the resulting reaction mixture was determined and adjusted to >10by dropwise addition of 10% sodium hydroxide.
Benzoic acid extracted from 123.16 g of sample required a 27.13 mL titration with 0.0792 M barium hydroxide. What is the percent benzoic acid in the sample?
Define Analyte and Titrant.
0.2061 grams of an unknown organic acid was dissolved in about 50 mL of water in a 250 mL Erlenmeyer flask and titrated against 0.1000 M NaOH solution using bromothymol blue indicator. 15.56 mL of titrant was used to achieve end point. Calculate the Neutralization Equivalent. Write answer with two decimal places only. No units please.
how would i find the average titre value in ml if I have 10% ethanol 1.3 ml (of water used) as titre value 1 and 1.1 ml (of water used) as titre value 2 ?
Mr. Clean recently bought a laboratory-grade sodium carbonate from a chemical company known as Brand X. He was supposed to use it in the production of detergents. Unfortunately, he was scammed by the company. He suspected that he purchased a crude so- dium carbonate so he tasked the Quality Assurance Department to determine the components of the purchased chemical. The chem- ist assigned to analyze the sample used double indicator method. For the standardization of HCI titrant, 0.1025 g Na2CO3 of 99.5% purity (FW: 106.00) required 8.20 mL of the titrant to reach the phe- nolphthalein endpoint. FW: NaOH (40.00), NaHCO3 (84.01), Na2CO3 (106.00) a. What is the molarity of the titrant? (use significant figures) The chemist obtained a 3.150 g sample and dissolved it in distilled water to produce a 50.0 mL solution. An aliquot of 10.00 mL was obtained and diluted in a 100.0 mL volumetric flask. A 50.00-mL aliquot of the diluted sample was taken and it required 25.70 mL of titrant for the…
In the experiment, we used titration to determine the total acid content ofsamples, which we reported in terms of molarity. Reporting acidity through pHmeasurements is quite different, in that we can only measure the amount of theacid in its ionized form. You were tasked to investigate a clear aqueous solutionof an unknown monoprotic acid. You decided to use two methods togather data.Method 1 – TITRATION: A 10. mL aliquot of the sample was diluted with 25 mLdistilled water. Two drops of phenolphthalein were added and then it was titrated3.54 mL of 0.048 M standardized NaOH to the endpoint.Method 2 – pH STRIP: You took 1 mL of the sample and used a pH strip toestimate the pH, which turned out to be around 3.3. Another 1 mL of the samplewas diluted with 9 mL of water. The pH was taken again and is now around 3.8.a) Calculate the molarity of the acid using the titration data.b) If we assume that the titrated unknown is a strong acid, predict thepH of the sample.c) Using pH strip results,…
0.02 M NaOH reagent was standardized using 0.1000 g Potassium hydrogen phthalate (204.22 g/mol) and it required 25.8 mL to reach end point.
Using titration to determine the relative molecular mass of an unknown acid using a standard solution of sodium hydroxide (NaOH) and phenolphthalein as the indicator. explain the method in depth. like you would in a lab report
Which of the following compunds is a weak acid? a) Phenol b) cyclohexanol c) ethanol d) 2-methyl-2-propanol In chromatography, the compound that is least soluble in the mobile phase
In the determination of the water hardness of a river water sample, the pH of the sample was adjusted to 12 instead of 10. Is there a positive error, negative error, no effect, or error could not be determined In terms of the ppm CaCO3 of sample?
Draw and label a complete laboratory set-up of acid-base titration using phenolphthalein as the indicator, using HCl as the analyte/sample, and using NaOH as the standard solution. Cite complete source/(s) if picture will be copied from the internet.