Green Slime, an uncharged organic dye, is present in 600.0mL of water at an unknown concentration. The sample is extracted with 75.00mL of cyclohexane. After the extraction, the absorbance of the cyclohexane phase, measured at 635nm in a 1.00cm cell, is 0.870. The absorbance of a blank (pure cyclohexane) is 0.007. Using Beer's L ...continues
solvents of synthetic varnishes
To my knowledge synthetic varnishes developed after ww2 are very hard to remove after about 20 years, since the molecules have by then interlinked. Subject is synthetic varnish removal of varnishes applied to to oil paintings. How controllable is monoethanolamine deluted with water, and glycol-ether as widely available as a w ...continues
problem attached
calculating molarity and molality
a sodium chloride solution has a molarity of 1.250 mol/L and a density of 1.050 g/ml. Calculate molality, the mole fraction of water, and the percent by mass of sodium chloride.
calculating distribution ratio at a specific pH
Given: an organic acid has a pKa value of 5.0 and a distribution constant of 3 between H2O and Toluene. Calculate the distribution ratio of this compound at pH=6.
The fraction of an analyte in the rth stage of a N stage separation if given by f(N,r)=(N!/r!(N-r)!p^r q^(N-r). Given: distribution ratios of 0.5 and 1.5 Stages 50 and 200 Phase volume ratio 0.3 What is the fraction of analyte in each stage and the stage number for analytes with the given dis ...continues
Two analytes A and B have retentioin times of 13.5 min and 19.5min, peak widths of 2min and 2.8min for a mobile phase composition of 20% methanol and 80% H2O on a 15cm C18 column which has a dead time of 1.5min. Determine the composition of methanol and H2O at which the capacity factor for A becomes 2. What is the capacity fact ...continues
Method set up for a chemical separation on an LC.
Given: 1. HPLC instrument/ 2. C18 reverse phase column/ 3. 1mM solution of each of the following compounds in Methanol/ 4. Mobile phase is methanol-buffer mixture: Compounds are 3 seperate groups: 1. Carboxylic Acids: a. Benzoic acid b.Phthalic acid c. Toluic acid 2. Amino: a. aniline b.4-aminotoluene c. or ...continues
Method development for chemical separation on GC instrument.
Given: 1. GC instrument 2. polysiloxane column 3. 1mM solution of each of the following compunds in methanol. Compounds divided into 3 separate groups: 1. Carboxylic Acid: a. benzoic acid b. Phthalic acid c. Toluic acid 2. Amino: a. aniline b. 4-aminotoluene c. ortho- pheylenediamine 3. Amino ...continues
I prepared a 1.0 mM solution of Benzoic Acid in methanol and I now need to convert it to 50ppm. ???? How???
