lab report #1

1. Presence of interfering contaminants in the sample is an example of this error. 2. A substance that shows the endpoint of titration 3. Substance that can burn skin and eyes

A 625 mg sample of sodium bicarbonate tablet required 7.30 mL of 0.9580N sulfuric acid solution to reach the methyl red endpoint. PRELIMINARY QUESTION: Which of the following statements is/are TRUE? I. The țitrant used is sulfuric acid solution. II. The end point is a red/pink solution. III. This is an example of direct assay titration.

Which of the following would you expect to produce a yellow solution with the ninhydrin test? A. Valine B. Piperidine C. Aniline D. trimethylamine A sample was observed to have the following responses to qualitative analysis. Insoluble in water - Insoluble in 5% NaOH - Insoluble in 5% HCI Formed a milky solution (precipitate) with alcoholic silver nitrate test What is the most likely identity of this unknown? A. Butanal B. Hexanal C. 1-chlorohexane D. 1-chlorobutane

QUESTION 2 One statement is not true regarding the determination of pka of Bromothymol Blue indicator by spectrophotometry. A. В. The absorption spectrum is the plot of absorbance against light wavelength and recorded by passing a light through According to Beer-Lambert law, the intensity of light absorbed or transmitted is directly proportional to a solution medium the color of the indicator in the solution C. D. The Bromothymol Blue indicator solution is a weak acid composed of The color of Bromothymol Blue indicator unionized acid and ionic conjugate base changes by changing the pH of the solution medium components Select answer

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0.2 mL of 10% sodium azide was added to 1.8 mL of 0.2% of YGM. What is the concentration of azide in this sample?

pH Indicator 1 4 7 8 9. 10 11 12 Phenolphtalein Colorless Pink Bromthymol Blue Methyl Orange Yellow Blue Red Yellow 1. What will be the intermediate color of bromothymol blue in a solution of pH 7? 2. A colorless household solution was tested with the three indicators shown above. The solution was colorless with phenolphthalein, yellow with bromothymol blue, and orange with methyl orange. What is the pH of the solution? Be as specific as possible.

Which reagent directly reacts with substance to be titrated? Method – bromometry: Br2; I2; KBr; KBrO3;

[attached is the given data] Questions:  1. What is the weight of epinephrine (in grams) required to make the prescription?  2. What is the volume of water (in milliliters) needed to make the preparation isotonic?

Procedure Preparation of Dilute Solution of Vinegar • Using a 10 mL pipette, transfer 10mL of vinegar into 100 mL volumetric flask.  • Dilute to mark of the volumetric flask using distilled water. B. Titration of Diluted Solution of Vinegar  • Transfer 25 mL of diluted solution to 250 mL Erlenmeyer flask.  • Add 0.5 mL phenolphthalein indicator. Set aside.  • Transfer 50mL of 0.110 M NaOH into a 50 mL burette.  • Titrate the diluted solution until the phenolphthalein endpoint (very faint pink).  • Record volume of NaOH used. Answer the question: What is the experimentally determined concentration of acetic acid in your vinegar solution: (Please give your answer to three significant figures.) ______ M Acetic Acid

An unknown sample containing mixed alkal (NaOH NaHCO or Na,CO) was analyzed using the double flask method, A 250 mg sample was dissolved in 250 m CO3 free water. A 20.0 mL aliquot of this sample required 11.3 ml. of 0.009125 M HCl solution to reach the phenolphthalein end point. Another 29.0 ml aliquot of the sample was bitrated to the bromocresol green endpoint using 31.1 ml of the standard acid. How many millimoles of the components are there in the original solid sample) 0-928 mmol No. 0.0103 mmol NaOH 0078 m N.CO Cannot be determined 012 mol NaC0, 197 minol NaHCO 129 mmol NaOH, 097ml Najco

In excess of alkaloidal reagent, did the precipitate formed dissolve or not? What is the evidence

please answer question 2 parts a and b. 2. 5.45 mL of 0.10 N NaOH was needed to titrate a 5.00 mL aliquot of grape juice to phenolphthalein endpoint.   a. Calculate the titratable acidity as g tartaric acid/100 mL sample.  b. Express the titratable acidity as a percent

An unknown inorganic salt produced a black precipitate when boiled with 5% thioacetamide solution. The salt likely contains a/an: O hard acid soft acid O hard base O soft base

Also explain why other options are in correct options need soon

Please explain, give correct answer and typed answer only as I can not understand handwriting clearly

What factor affects the ‘strength’ of a buffer? Why was benzoic acid used as a solvent when making up the glucose stock standard solution?

Answer step by step please.

Choose the answers from the box Please answer 10,11,12,13,14

Calcelate mokality of 52 (음)/ 아 to Solalicn. A) 0.65 p) 0 구2 () o.81 D) 0.94 Calulete pt of 0-001 M oK H Poa solation A) ) c) I.5 D) 2.5 NGOH 2 lit Hy soq mixed with Calulete pH of solution N of Nof slit of then A) 8.25 8) S.75 C) 7. 55 D) 9.45

Understanding of food analysis methods.  Principles of method described compared to other techniques.   1 The MOHR Titration, AOAC Method? What is it and how does it work? How can it be used to quantify salt in a sample. 2 Are there any advantages and/or disadvantages of this method?3 Are there any alternate methods better than the Mohr Titration toquantitatively determine salt in a sample? 4. Diseases with recent statistics? Refer to World Health Organisation? 5. Why analayse salt? 6. Consumption? 7.  Main aims of study?

15. A 300.00 mL solution of 0.00165 M A2B5 is added to a 230.00 mL solution of 0.00380 M C2D3. What is pQsp for A2D5?

True/False Indicate whether the statement is true or false. Write T if the statement is true while F if statement is false on the before each number 10.Phosphoric acid behaves as a dibasic acid when titrated and using thymolphthalein as indicator. 11.100% inspection has many advantage over sampling inspection because the statistical sampling plan may give better quality assurance than 100% inspection. 12.Phenolphthalein is colorless in basic media. D

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4. The equivalence point of an acid-base titration curve is at pH 8.1. Which dye can be used as the pH indicato for this titration? A. A dye with a pK₂ of 3.9 B. A dye with a pK, of 8.0 C. A dye with a pK, of 6.2 D. A pH indicator cannot be used for acid-base titration.