lab report #1

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.

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

Claire needs to determine the identity of a hydroxide precipitate in an unknown analysis. An HCl titrant required 98 mL to reach the methyl orange endpoint with 0.5401 g of NaCO3 (99.95 %) dissolved in 50 mL freshly boiled distilled water. She then mixed the precipitate in 25 mL of water then filtered out any remaining solids. Titration of the solution required 51.8 mL of standard HCl titrant to reach the phenolphthalein endpoint. What is the concentration of the HCl titrant (M)?  What is the concentration of [OH-] (M)?

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.

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

Also explain why other options are in correct options need soon

Following the monograph procedure, a 724-mg of aspirin (MW=180 g/mol) dissolved in 18.5 ml of cold neutralized alcohol. This solution was then initially titrated with 0.101 N sodium hydroxide solution, then later neutralized with 0.104 sulfuric acid.   1. What is the total volume (mL) of excess titrant used in the titration? a. 56.400 mL b. 52.000 mL c. 44.600 mL   2. What is the milliequivalent weight consumed by the acidic titrant? a. 1.5392 g-meq b. 2.0907 g-meq c. 1.4948 g-meq d. 2.1528 g-meq   3. What is the milliequivalent weight consumed by the basic titrant? a. 5.8656 g-meq b. 1.5392 g-meq c. 5.6964 g-meq d. 1.4948 g-meq   4. What is the difference of milliequivalent weight consumed in the reaction? a. -4.1572 g-meq b. 4.3708 g-meq c. 0.5515 g-meq d. 4.1572 g-meq   5. What is the percentage purity of the sample?   6. What is the titer value (mg) based from the specific type of titration?

Using the Winkler method to determine the dissolved oxygen level in a water sample, which indicator is used to observe the endpoint of titration? a. Phenolphthalein indicator O b. Litmus test strips Universal pH indicator O d. Starch solution

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