Consider a separation performed on a 30.0 mm long open tubular column with a 0.50 mm diameter and a 2.0 µm thick stationary phase. Compound A eluted at 12.63 min, compound B eluted at 13.24 min, and the unretained solvent eluted at 1.205 min. What are the adjusted retention times, t'a, and retention factors, k, for compounds A and B? TRA LR,B = KA = КВ = min min

You prepared a stock solution by dissolving a compound with the molar mass of 110.65 in a 100 mL volumetric flask. Then you removed a 2 mL aliquot and placed it in a 250 mL volumetric flask and dilute it to the mark. The absorbance of this diluted solution in the 250 mL volumetric flask at 288 nvm was 0.421 using a 2.50 cm path length curvet. The molar absorptivity for this compound at 288 nvm is 65000 M-1cm-1 How many ng of the compound were used to make the stock solution?  a)1.44 b)0.96 c)0.72 d)1.22 e)2.87

A 20-cm long packed column was used to perform the separation of A and B by LC. TRA=16.28 min, TR,B=17.50 min, WA=1.11 min, WB=1.19 min, tм=1.30 min. (a) Calculate the retention factor (k') for A and B. (b) Calculate the average number of theoretical plates and plate height.

A student performed three DCM layer titrations in Part 2 and they reported the following measurements: Final Burette Reading Initial Burette Reading Volume of DCM Aliquot Final Burette Reading Initial Burette Reading Volume of Sodium Thiosulfate Determination #1 Determination #2 Determination #3 29.99 mL 22.78 mL 7.21 mL 28.56 mL 1.21 mL 27.35 mL 37.45 mL 29.99 mL 7.46 mL 28.89 mL 1.08 mL A 27.81 mL 44.86 mL 37.45 mL 7.41 mL 28.68 mL 1.00 mL 27.68 mL Which determinations were the student's 'best two'? Calculate the percent difference for the 'best two' and show the complete calculation. Note that the concentration of standard sodium thiosulfate, which the student used, is unknown.