How can I know that a compound/substance is amphoteric?
84935
amphoteric is substance which can act either as an acid or a base. Simply react the substance (that you want to test if it amphoteric or not) with an acid, continue to react the same substance with a base. If the substance react with both acid and base, it must be an amphoteric.
186407
One way to tell is to look up the heats of formation for the reactants and products.  Add all the reactants up and all the products up.  Subtract the reactants from the products.  If the answer is negative, the reaction is exothermic.  \n\nThe other way is to actually carry out the reaction and see if it liberates heat or not.
933669
aldehyde\nthe name of the compound is propionaldehyde
36835
I think you might mean absinthe.  I don't know about its chemical composition, but here is a website that lists its various ingredients. \n\n\nhttp://absinthesupply.net/absinthe/what-is-absinthe.html
807972
You must to know the density, d. Then use the formula m = vd and you will know the mass of compound. Divide m by M (molar mass) and this is number of molles, n\n   n = vd/M
1028869
For some values of difficult to test.\n\nTypically, inorganic compounds are ionic in nature, so you're more likely to get chlori*d*e than chlorine (you do appreciate the difference, right?) so you can do things like addition of silver nitrate to get a ppt.\n\nHowever, you can also run mass specs and things - chlorine has a typical splitting pattern here based on isotopic ratios and so in this instance it's probably just as easy to detect it in organic (if not more so) than in inorganic compounds
64922
Information you are looking is really hard to find, drugs are illegal so there isn't any legal refrence shows the amount of them, many of them like Amphetamines and LSD are lab products and don't import.\nThere are estimations but most of them are rough.
839410
This compound is an amine.  You can identify it by the NH2 (amine group) at the end.  You did a fair job with the structure considering the limits of the text here.  I am sure you realize that two of your carbons do not have the correct number of bonds.
135532
You can either look it up or determine it experimentally.\nI cant get much more specific without additional details.
542320
I would just recommend looking at a can and seeing what is the propellant.  We could guess all day, but as long as we don't work in a silly string factory we couldn't be absolute.  Alot of that kinf od informations i proprietary.  But how about this:\nPropellant\nSomething that dries fast (isopropyl)\nA plasticizer to keep the goo gooey\nsome other stuff
217892
Apart from the precipitation reactions (AgCl and BaCO3 form insoluble compounds, although HCl will dissolve BaCO3), there is flame colouring for identifying the alkali and earth alkali metals (Na yellowish orange, Li reddish, Ba green), there are pH measurements (HCl acidic, NaOH and Na2CO3 basic, rest neutral), and you need to test an oxidant to identify the sugar solution. This ought to give you a matrix which gives only one possible identification for each test (with deionized water failing all tests).
178785
Disregard the previous gibberish.\nTo estimate purity you need to be able to interpret the spectrum to determine which peaks belong to your product.  Assuming that you can do this, the entire spectrum needs to be integrated and from the integrals of the individual peaks you can determine the ratio of impurities present and thereby estimate the purity of your product.
989710
1. impurities in the compound\n2. temperature of the surface thats heated on\n3. old lab furniture.\ncant say more!
653068
amphetamines are weak bases with a pKa of 9-10.  amphetamines are an amine-based drug.  amines cause ionization of water to form OH- ions.  this will result in a basic solution.
435843
Most compounds contain ligands or are charged so as to be physiologically useful to the body. For example, lidocaine is a sulfate salt, as the amine group in the compound is protonated.\n\nThe salt is listed second because it's just a form of the compound (e.g. the way that the compound is being administered).
210155
The current way would be ion chromatography.  There are older less reliable methods.  You test for the calcium separate form the anions.  The calcium can also be donw by ICP or AA.
488883
Here's one source that has a "universal indicator (pH 2-10)".  It may not be the only one:\n\nBromothymol Blue 0.08%\nMethanol (solvent)\nMethyl Red Hydrochloride 0.04%\nPhenolphthalein 0.02%\nThymol Blue  0.1%