method as follows: punty of an ibuprofen sample was determined by a reversed phase HPLC Y A calibration curve of peak area versus concentration (ug/mL) of pure ibuprofen was constructed The ibuprofen şample for analysis was prepared by taking 10.0204 g of powder and dissolving it in/1Lbf distilled water (solution A). 1 ml of the latter solution was further diluted to IL with distilled water (solution B). Solution B was analysed by HPLC analysis Results The equation for the best-fit line of the calibration curve is: y=26820x-1323.8. The average peak area for the ibuprofen sample (solution B) was 266796.2 Calculate the percentage purity of the ibuprofen powder,

To 47.62 ml of wine were added 5 mL of concentrated KI solution and 32.11 mL of solution containing (0.7557 g KIO 3)/(100.00 mL solution). The wine+reagent mixture was acidified with 10 ml of 1 M HCI to create a known number of moles of I 2 by the reaction 10 3 + excessl + some H*-> 31 2 Some of this I 2 immediately reacted with the sulfite in the wine sample by the reaction SO 3 +12 --> products we don't care about The left over I 2 was titrated to a starch end point with 10.14 mL of 0.04521 M thiosulfate solution, by the reaction 12+ 25 20 32-> products we don't care about What is the concentration of sulfite in the wine, expressed in mM?

Consider Table 1, which lists the volumes of the Fe3+ and SCN- solutions used for the continuous variation method. Note that each of the stock solutions is 0.002 M before mixing. What are the initial concentrations of Fe3+ and SCN- for solution 4, where the volumes are both 5 mL? [Initial meaning after they are mixed, but before]they reach equilibrium)

What mass of MgCl₂ 6H₂O is required to make a 0.200 dm³ stock solution containing 25.0 ppm Mg(II)? What volumes of this stock solution are required to make 10.0 cm³ standard solutions containing 5.00, 1.00 and 0.10 ppm Mg(II)?

using the given values for trial 1, how would you find the mass of pure liquid H2O2?

Solve for titer. Pls show me the solution or step by step process so I can follow. Thank you

5) Retention factors for three solutes separated on a C8 nonpolar stationary phase at pH = 3 are given. Eluant was a 70:30 vol/vol mixture of 50 mM citrate buffer and methanol.  a)Draw the dominant chemical structure of each of the substances at pH = 3. b)The retention factor for acetophenone is 4.21, for salicylic acid is 2.97, and for nicotine is zero. Explain the different retention factors.

How do I prepare these solutions? I do not know what volumes or molarities to be added from the initial step. Thank you.  1. Prepare a fresh stock solution of 50 cm3of 0.2% ascorbic acid. 2. Prepare 5 standard solutions of ascorbic acid in volumetric flasks of 25 cm3. 3. To each volumetric flask add 0.5 cm3 of 0.5M acetate buffer and different volumes of 0.2% ascorbic acid to make 0.01 mM, 0.02 mM, 0.03 mM, 0.04 mM and 0.05 mM solutions. Dilute to the mark with distilled water.

Calculate the water hardness (mg L-1 of CaCO3)  (i.e. calculate the mass of CaCO3) please show working out. thank you :) Sample No. 1 2 3 4 Final Burette reading (mL)   24.40 46.90 24.70 47.20 Initial Burette reading (mL) 0.10 24.40 2.10 24.70 Final-Initial Titre (mL) 24.30 22.50 22.60 22.50

3. This is the standard procedure for determination of nicotine in urine. A 1.00mL sample was placed in a 12mL vial 5-aminoquinoline was added as the internal standard (5 ug). The sample was monitored using mass spectrometry at m/z values for nicotine (84) and the internal standard (144). Given the following data determine the concentration of the two unknown samples Nicotine (ug/L) Area Area 12 0.056 0.059 51 0.402 0.391 102 0.684 0.669 157 1.011 205 Unknown 1 Unknown 2 1.278 0.51 1.18 1.063 1.355 0.53 1.32