Please help with the following problem. Suppose that you must go into court and testify as to the level of X in the river water. Your lawyer is concerned that your analytical results are lower than they should be because you cannot extract with benzene (distribution Ratio K=4) all of X from your samples. Assume the concentra
A mixture of organic acids was separated by reversed-phase liquid chromatography. The data obtained for the chart recording were as follows: For acid A, the peak appeared 22 cm after injection with a full width at baseline of 8 cm. For acid B, the peak appeared 34 cm after injection with a full width at baseline of 6 cm. A non-r
A chromatogram would feature lines instead of peaks if: a) the best equipment available is used b) the separation is done by capillary electrophoresis c) if the temperature nears (or is equal to) the absolute zero d) neither of the above cases would suffice. B. Most modern chromatography instruments are equipped with: a)
In thin layer chromatography what is the Rf's mean? How are they used? What factors affect the Rf of a compound?
In the attached paper, the authors claim that F-doping enhanced surface acidity. Why does the presence of fluorine increase surface acidity? Reference: Li, D., Haneda, H., Hishita, S., Ohashi, N., & Labhsetwar, N. K. (2005). Fluorine-doped TiO< sub> 2</sub> powders prepared by spray pyrolysis and their improved photocatalyt
Please help with the following problem: Refer to the GLC traces given in Figure 6.16. These are analyses of the various fractions collected during the fractional distillation of the mixture of cyclohexane and toluene. The weight and mole correction factors (flame ionization detector) for cyclohexane are 0.84 and 0.78, respec
Lab 3: Solubility of Organic Compounds Objectives: - Understanding the relative solubility of organic compounds in various solvents. - Exploration of the effect of polar groups on a nonpolar hydrocarbon skeleton. Introduction: The solubility of a solute (a dissolved substance) in a solvent (the dissolving medium) is
1. Why is it dangerous to heat a liquid in a distilling apparatus that is closed tightly at every joint and has no vent to the atmosphere? 2. In your distillation of the binary mixture, which fractions contained more of the higher boiling component, the earlier fractions or the later fractions? expriment procedure
I conducted HPLC analysis of myoglobin and hemoglobin using a C18 and C4 column. Both proteins were in a buffer solution only. On the C4 column the order of the peaks was a reverse of the C18 column. The chromatographic output showed two peaks. Looking at the UV absorbance, I can attribute one of the peaks to the heme group (
Hey I am did a multiweek experiment doing a protein purification of Glutamate-Oxaloacetate Transaminase (GOT). I have a few questions about my experiment. 1. How does protein purification help in the real world? What's the larger picture? 2. I preformed a GOT Assay, GDH(Glutamate Dehydrogenase) Assay, Folin-Ciocalteau Ass
I recently did an experiment on high-performance liquid chromatography I am having a little trouble in the introduction. The introduction should just be a description of High-performance liquid chromatography and what I will learn from the experiment. I wrote a draft but my TA said that it could use some work. I was wondering if
Hey I am about to do a lab to determine the amount of caffeine and sodium benzoate in soft drinks via HPLC. To prepare I had to answer a series of questions before the lab. I am confused on some of them and request your help. The questions are: Why is it necessary to perform the HPLC separation at a pH of 3? How does the pH a
Please see the attached file for the fully formatted problems. 1.Based on the following figure explain which particle size produce the best resolution in HPLC and why? 2. To find the Ce4+ content in a solid, 4.37 g were dissolved and treated with and excess of iodate to precipitate Ce(IO3)4. The precipitate was filtered, w
Introduction to the Ideal Gas Law A balloon is floating around outside your window. The temperature outside is 31 , and the air pressure is 0.700 . Your neighbor, who released the balloon, tells you that he filled it with 3.60 of gas. What is the volume of gas inside this balloon? Express your answer numerically in liters.
A. How many peaks would you expect to fin in the NMR spectrum of caffeine? B. What characteristic absorptions of bands would you expect to find in the infrared spectrum of caffeine?And show the infrared spectrum C. the vapor pressure of 1,2-dipheneylethane, p-dichlorobenzene, and 1,3,5-trichlorobenzene are 0.06, 11.2,
1. in gc (gas chromatography), what is the stationary phase? what is the moving phase? 2. as with the other chromatographic techniques we've studied, the polarity of the compounds affects their separation in gc. what is the other dominant factor that affects separation? 3. what would be the effect of increasing column temperat
I did a lab on column chromatography and thin layer chromatography, and our sample was a spinach extract. I am trying to figure out if there is a correlation between the partition coefficient and the Rf used in thin layer chromatography. Is there one? For the column chromatography we used a 9:1 hexane: acetone, thenn 1:1 h
1. The relative movement of the substance is related to polarity of the substance. The TLC sheet is coated with highly polar silica gel and the solvent has a much lower polarity. Explain the relative Rf values on a structural basis. 2. Explain why leaves " change color" in the fall. 3. How does the Structure of chlorophyll
The advantage of treating separate samples of a protein with two or more enzymes when sequencing a protein is that the products are a. more homogeneous b. sequenceable with out further chromatography c. fragments with the same N- and C-terminal amino acids d. fragments with sequence overlaps e. all are true
Based on predicted pI (for example, a pI for turnip peroxidase is 9.10), how can you use DEAE-sepharose to further purify peroxidase?
1. If the active site of a dipeptidase contains a glutamic acid residue (pKa 3.3) and a histidine residue (pKa 6.7), both of which must be charged for the substrate to bind, what is the optimal pH for substrate binding? 2. Lysozyme catalyzes the hydrolysis of C-O-C bonds between sugar residues in bacterial cell walls. The p
1. What is the amino acid sequence of the peptide? The complete hydrolysis of an unknown nonapeptide revealed the presence of Glu, Val, Val,Gly,Lys, Lys, Tyr, Thr and Phe residues. The first amino acid to be detected as a phenylthiohydantoin derivative on Edman degradation of the peptide was glutamic acid. The only amino ac
In trying to deduce a primary structure of an peptide sequence... When does a polypeptide NOT contain a free carboxyl group? Are all peptides linear (or can they have a cyclic C-terminus)? What happens when treatment of the intact peptide with 2,4-dinitroflourobenzene (followed by complete hydrolysis and chromatography) y
Question: Sketch the expected chromatographic elution profile (protein concentration vs elution volume) if a mixture of these proteins is applied to a weak anion exchange resin such as DEAE cellulose at a pH of 7. Label and show the salt gradient used for elution. Protein: (A), pI 8, MW 25000 (B) , pI 10, MW 10000 (C) , pI
Caffeine is soluble in ethyl acetate. Do you think that the purity of your product could be checked by TLC using ethyl acetate as an elution solvent? Explain.
Experimental proceedure for Separation of Chiral compounds by High performance liquid chromatograph.
Seperation science of enantiomers which are very difficult to separate otherwise.