Homework Essay

HOMEWORK 1. Calculate the percentage of transmittan absorbed by a sample with an absorbance: i) 2 and ii) 0.1.

2. Calculate the pKa value of the aniline in procaine from the data given below. Absorbance of a fixed concentration of procaine in 1 M HCl at 296 nm is 0.031; absorbance in 0.1 M NaOH is 1.363; absorbance in buffer at pH 2.6 is 0.8337.

3. Calculate the content of methoxamine hydrochloride in a injection from the following information:
The assay was carried out by diluting 1 mL of the injection to 100 mL with water and 20 mL of the diluted injection was then diluted to 100 mL. An absorbance reading of the final dilution was taken at 290 nm with a UV spectrophotometer. Absorbance of diluted injection solution was 0.542. Abs (1%, 1cm) value of methoxamine hydrochloride at 290 nm is 137.

4. Determine the concentration of the following injections:
Isoxsuprine injection is diluted as follows:
Diluted 10 mL if injection to 100 mL and then 10 mL of the dilution to 100 mL. Absorbance reading at 274 nm is 0.387. A (1%, 1 cm) value at 274 nm is 73.

Haloperidol injection:

i) Add 15 mL of 1 M HCl to 5 mL of injection. ii) Extract 3 times with ether, washing the ether extracts with 10 mL of water. iii) Combine the aqueous layers and dilute to 100 mL. iv) Take 10 mL of the diluted aqueous solution and dilute to 100 mL. v) The absorbance reading at 245 nm is 0.873; a (1%, 1 cm) value at 245 nm is