Based on your structures above, provide explanations on why some of the observed retention factors change with pH of the mobile phase.

Nites

You are going to analyze an aspirin tablet using a UV-visible spectrophotometer. You crush an aspirin tablet in a mortar and pestle until a powder forms. Then, you weigh some of this powder and add it to a 25 mL volumetric flask with 8 mL buffer to raise the pH and dilute with DI water to the mark. How would you prepare a method blank for this method?

Question 1 for data analysis

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,…

The pKa of acetic acid is 4.76. What volume of 2 M HCl can be added to 100 mL of 0.1M acetate buffer at pH 4.76 before it is 90% titrated (i.e., is at the end of its buffering capacity)?

Prepare 500ml of 2M of Tris-HCI buffer with pH 8.9. Tris base molecular weight is 121.14 g/mol. Explain the preparation procedure for Tris buffer.

You are a formulation scientist preparing a semisolid topical scream. Your formulation requires that a 1000 mL solvent of pH 7.4 phosphate buffer be prepared to suit the pH of the skin. To prepare the buffer, you must use monobasic sodium phosphate (NaH2PO4) and sodium hydroxide (NaOH) since these two ingredients are compatible with your other ingredients in the cream. NaH2PO4 + NaOH → Na2HPO4 + H2O 1. The Ka of NaH2PO4 6.2 x 10-8. Using the Henderson-Hasselbalch equation, calculate the molar ratio of [conjugate base]/[weak acid] that must be used in preparing the buffer. 0.39 B. 0.78 C. 1.56 D. 2.34 2. There is an available 50 mL of 0.2M NaH2PO4 in the laboratory. Convert this first to the moles of NaH2PO4. The molar mass of NaH2PO4 is 119.98 g/mol. 0.005 mol B. 0.010 mol C. 0.025 mol D. 0.045 mol 3. Given the number of moles of NaH2PO4 available as computed above and the molar ratio calculated, which of the following moles of NaOH when added to NaH2PO4 will produce the…

The following data was collected when a 25 mL sample of an unknown acid is titrated with a 1.00 M NaOH Solutio. Determine Ka for the unknown acid.

A buffer was prepared by mixing 700 ml of .70M lactate solution and 800 ml of a .40 M lactic acid solution. what is the pH buffer, assuming a final volume of 800 mL. the pka for lactic acid is 3.97.show detailed solution.