i used petroleum ether : acetone in 9:1 ratio.and i got a doubt that what is the effect of solvent on chromatography paper i.e what if i used another solvent? I know that the values change but i am not able to understand the concept behind it.
130458
one of your solvents is more polar than the other (in this case acetone) the substances to be separated by chromatography will move the most in a solvent mixture they are most similar to. Remember like dissolves like. So if your unknown is easily dissolved in a non-polar solvent like hexanes then a non polar solvent will move it the most on the paper. If your substance is very polar, IE. an organic acid. It will stay near the bottom of your chromatography paper, when using a non-polar solvent mixture. 9:1 ether:acetone is actually quite non-polar, you can progressively increase your solvent polarity by making multiple solvent mixtures with changing ratios 8:1, 5:1 etc.   Obviously, you must use a new piece of chromatography paper each time you run a new experiment (unless your spots didn't move at all!). The basic concept of these experiments is polarity and how it relates to separating a mixture. Remember, like dissolves like!
436204
tiny amounts of chemical can stick to differnt things, like stir bar, stir rod, thermometer and if you remove these items before the experiment is over then you remove some chemicals.  Other kinetics events that your not considering. as in pressure, humididtym and so on.  If you used a Ph probe then maybe it wasn't calibrated right or isn't properly maintained
465640
Assuming the OTs is tosylate, your answer is correct. It should have the UIPAC name of 1,2 dimethyl butyl ethyl ether. The number starts from the ether bond - I think.\n\nIf this is a true SN1 reaction, racemisation will be practically complete and the products will show no optical activity - generally. SN1 reactions generally proceed through the carbonium ion intermediate.\n\nThe final product will have an assymmetric carbon atom (marked with the *). Thus the two mirror images will not be superimposable and optical activity with result. Racemisation will generally result (as for SN1 reactions) and equal amounts of both isomers will form and the optical activity will nearly be zero.\n\nThe wedged and dashed lines indicate spatial arrangement. The wedged line indicate the group comes out of the page and the dashed line indicated going into the page. This convention is used to shown spatial arrangements for demonstration of the stereo chemistry of reaction pathways.\n\nHit the textbook my old son......
397152
Suspected trick question.  The volumes included are irrelevant.  You know the molecular weight (66000 Da) and you know how many micromoles you need total in each solution.  What does it matter if the one micromole is in 1 ml or 10K gallons?  You know it only contains one micromole.  Divide the molecular weight by 10^6 and you're done.  (or you have not stated the problem correctly)
449412
how were you measuring the pH? if it was a pH meter maybe it wasn't calibrated correctly/ recently?? or if it was with litmus paper.... maybe it went bad? I'm not sure if it can... check and see if there could have been an expiration date. i don't think temperature would have that drastic of an effect unless you did the experiment at pH7 and a seriously high (like about 60C) temp and the other ones at room temp or 37C (body temp)... sorry i cant help anymore then that, that's very strange!
415737
Consider a primary alcohol that has a structure like C--OH\n\nthen consider a tertiary alcohol that has a structure similar to \n          CH3\n           |\nH3C--C--OH\n           |\n          CH3\n\nIn a primary alcohol such as the one shown above, the distribution of charge is relatively polar due to the presence of only one other carbon atom with one very electronegative oxygen atom. In a tertiary alcohol, there are four carbon atoms versus only one electronegative oxygen atom. Therefore, in the tertiary carbon, the polarity is greatly less because the polarity is balanced by the presence of so many carbon atoms around the molecule.
490753
If it is a school project, go through the department chair to have them obtain the supplies for you, and give you the proper supervision.\n\nIt would raise the eyebrows of the authorites to do otherwise, as hexane could be used in meth production just like ether.\n\nIt is an explosion hazard similiar to ether, a proper lab at school is the place to use this.
242754
9 weight percent\n\nhttp://en.wikipedia.org/wiki/Starting_fluid\nhttp://en.wikipedia.org/wiki/Diethyl_ether\n\nhttp://www.vs.ag/ida/index_dmefact.htm
276982
I don't know that you can, different solvents react differently to pressure, so I don't think it's a one eqaution fits all kind of process.  That's why they all have different graphs for phase vs temperature/pressure.  I'm sorry.\nSounds like you have a pretty high boiling point though, the things I've taken off that had to be real high temp were water, toluene, and pyridine.  Could it be one of them?  They smell pretty different, so you'd know which.  \nThat's an interesting question though, I've never stripped a solvent that I didn't know what it was.
456704
molecular wt of acetone:  58 g/mol\n\nmass of acetone in bottle:  vol x density = 314 x .788 = 247.4 g\n\nmol of acetone = mass/mol wt = 247.4/58 = 4.27 mol\n\nthere is 6.02 x 10^23 molecules in a mole\n\nso 6.02 x 10^23 x 4.27 = 2.6 x 10^24 molecules
461290
Hi - here are some ideas without seeing your actual data.  First - the system was too hot during transfer to  the membrane - be sure you aren't running it at too high  a voltage.   Second, not an issue with the  blot,  but with  the gel  - was it expired?  not fully polymerized? were the  wells free of debris when loading  samples?   sometimes with highly concentrated samples, especially cell lysates,  this  can  happen  because  of  viscosity  in t he  sample  (from  DNA for example). good  luck.
478652
The samples must be homogenously ground to enable the solvent to fully soak into the sample and extract the compound you want in question. Also there is a question of statical averages so a uniformed powder sample is the best for this process. If the sample is lumply or too big the solvent can't fully soak into it and wherefor not all of your compound in question is extracted by the process (Then the solvent fills up the soxhlet thumbie (sp)). If this happens you will get a incorrect value then you come to do the maths in determinating the amoult of the coumpound in question.
151095
Retention times for chromatographic techniques are usually a function of column length and composition, so listing the retention times from longest to shortest is probably just convention. However, the analyte with the longest retention time should (in theory) be separated best from any other analytes in your solution, but should also be most distorted when it reaches the detector. Perhaps scaling these graphs in such a way is an attempt to illustrate this point.
154332
Paper chromatography is a modern method used separate mixtures. Paper chromatography uses paper as the stationary phase and a liquid solvent as the mobile phase.\n\nYou will use paper chromatography to test food colorings to see if the color results from a single dye or mixture of dyes. If you cannot get food coloring you can use colored felt pens or other water soluble coloring pens. Your exercise is simple but uses very essential principles. An optional part of the activity is to check a household product for the presence of the same dyes that are in food coloring.\n\nThe technique relies on the idea that the solvent and the paper both have an attraction for the components in a mixture. The solvent creeps along the surface of the paper. If a material is placed on one spot on the paper and is soluble in the liquid solvent, the material will be dissolved when the solvent moves over it. The material will move along with the solvent. Each compound in a mixture will have its own characteristic balance of attractions to solvent and to paper, so all will not move at the same speed. Eventually this difference in speed will separate the compounds.\n\nIn paper chromatography when the conditions are kept constant, a particular compound always travels a fixed percentage of the distance traveled by the solvent front. The ratio of the distance the compound travels to the distance the solvent travels is called the Rf value. The symbol Rf stands for "retardation factor" or "ratio-to-front". It is expressed as a decimal fraction. When the conditions are duplicated, the same average relative positions will turn up for the solvent and solute; thus the Rf value is a constant for a given compound. The Rf value is a physical property for that compound. The Rf value is useful in identifying compounds, but other properties should be used in combination with the Rf value to confirm compound identification. Since it is difficult for different laboratories to exactly duplicate conditions for a chromatography experiment, Rf values are more useful for comparisons within one lab than for comparisons of data from different labs.\n\nSubstances that are not colored can also be separated by chromatography. They are detected using ultraviolet or black light. These substances appear to glow in the dark.
491932
Chromatography relies on the partitioning of different molecules from each other between a moving liquid phase and a static solid phase.  The more time the molecules spends in the static phase, the later it appears on the chromatogram.  The peaks on the chromatogram are broader and shorter at the end because they have spent longer "in the system" and have had more time to be affected by random motion, so they have a higher variation around the mean.
506520
you know you have got 152g total. So 1.8g/ml means you have got 152/1.8 for volume.Now just use MW KOH. Molarity will be moles KOH per litre, molality will be moles KOH/kg of solvent and Normality in this case will be the same as molarity but written  with symbol N.\n\nAs an aside the density of this solution would not be anywhere near 1.8g/ml, are you sure you have this right?
639748
So you need chlorobutane to run a column?\n\nWhat about something similar, in terms of polarity, like chloropropane or chloropentane?\n\nI was going to run a column once based on results from TLC using a pentane/acetone mixture. The lab ran out of pentane and the stock room was closed. My undergraduate research advisor suggested hexane instead. We tried it, it worked, and I was able to get the separation.