How can you determine the concentration of an unknown concentration of methylene blue dye?
139895
2 ways come to mind.\n\nYou make a series of solutions of increasing concentration as well as a blank (deionized water) and measure their absorbance in a spectrometer. You find a regression of the data and figure out the methylene blue based on its absorbance.\n\nStandard addition. You take unknown absorbance and add increasing concentrations of methylene blue to it. Graph the data and figure out the concetration corresponding to the y intercetp.
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.
244555
For a unknown solution concentration a pH meter , a hydrometer and a thermometer or a combination of the factors can be use to determine the solute concentration in a granulated cylinder
808549
M=molesof solute/Liter of solution\n\nM= molarity
1030039
I think you might mean methylene blue. Please confirm and let us know which country you are in.
1115546
You can experimentally calculate the molar absorption coefficient for methylvilolet. Prepare one molar (1M) solution of methylvilolet (c). Measure the maximal absorbance (A) for methylvilolet in a specific wavelenght on a spectrophotometer.Use the equation were given in below.\n\n                   A=e. l . c\n A=absorbance\n e=molar absorption coefficient (L/mol . cm)\n l= 1 cm (path of light)\nc=concentration (1M)
485893
Check on the internet for the ratios used by comercial factories, then prepare a solution from glycol and water in the given proportion. That's all!!!
518068
Make a solution saturated with calcium hydroxide.  If there is precipitate calcium hydroxide then that means there is as much dissolved calcium hydroxide as possible.  Filter the solution to get rid of the solid.  Now you have a saturated solution, and your objective is to determine the molarity of this solution.  Measure the volume and keep track of this measurement.  To determine the number of moles of Ca(OH)2, titrate it with strong acid like HCl, and see when the pH reaches 7.  When you titrate, keep track of the amound of acid you are adding, and the current pH of the solution.  At pH=7, the number of moles of HCl you added is equal to the 1/2 the number of moles of Ca(OH)2 (because the molarity of H+ and OH- are equal).  Take this number of moles and divide it by the original volume.  This value is the concentration of hydroxide [OH-].  Half of this value is the concentration of calcium [Ca++].  Ksp = [Ca++]·[OH-]²
261798
The aqueous solubility of AgNO3 at 20C is 67.8 (solubility is 100*m2/(m1+m2) where m2 = mass of solute and m1 = mass of solvent).\n\nRearraging the equation gives us m2 = (m1*67.8/100)/(1-67.8/100).  or\nm2 = (m1*.678)/(1-.678) = 210.56g of AgNO3 @ 20C\n\nAt 50C the aqueous solubility of AgNO3 is 79.2 so\nm2 = (m1*.792)/(1-.792) = 380.77g of AgNO3 @ 50C\n\nTo find the amount needed to make the second solution saturated we must subtract answer 1 from answer 2.\n\nWe find that 170.21g of AgNO3 must be added to make the solution saturated at 50C.
836016
Here is a good guide\n\nhttp://dbhs.wvusd.k12.ca.us/webdocs/Stoichiometry/Limiting-Reagent.html
198892
There is no such colorimetric estimation but there is a way to identify if your test is not going wrong. U need to look into the colour when it is becoming greenish from orange (that of potassium dichromate+mixtures). If it turns to green then add some more dichromate (please note that u should be aware of how much you are adding). Then continue your test. This might give you result.
754842
thats not so hard... all you have to do is titrate it against an acidic solution of known concentration that has a mole ratio of 1:1with sls. add a indicator ( phenolphthaleine) to find the endpoint and that should do it.
5197
More information is needed.  What is the concentration is it a percentage or a molarity.\n\nDo you need to find the concentration or just the amount of alchohal?
245982
Sorry, can't help. You use different units than I do.\n but concentration(mol per dm3) = no. of moles(mol) divided by volume(dm3)
952788
A=E*d*C\n\n(d=length of the path of the light through the solution)\n\nIf you have only one value of absorbance then obviously there is no way of determining the concentration without the molar extiction coefficient (E).\n\nIn practice even if you know E, you don't use it to find the unknown concentration. Instead you measure the A of standard solutions and do a standard curve. From the equation of that curve (which you find using linear regression) and the value of A of your sample you calculate the unknown amount. \nThe standard curve doesn't need to be A vs mole/lt. It can be A vs anything e.g. g/ml, mg/ml, ppm or even just g, mole, etc. the only thing that changes is what the slope represents.\nFor example for A vs mole/lt the slope corresponds to E*d, for A vs g/lt the slope corresponds to E*d/MW, etc.\n\nIf you  always have the same volume of sample you can do the curve A vs grams directly. Then if V is the volume of the sample, the slope corresponds to E*d*V/MW\n\nEven if your standard curve is expressed in moles/lt you can convert it to grams. You just need the MW of the compound and the volume, not E...
899107
Quantitative = amount \nSpectrophotometric = wavelength specific measurement\nAnalysis = determination\n\nCombining these terms gives you "the determination of the amount of material present by the use of specific wavelengths of light".\n\nMany compounds have chromophores, or specific portions of the molecule, that absorb energy of a specific wavelength.  Therefore, using a spectrometer, you can determine that a light source produces a given amount of energy at some predetermined wavelength.  When the analyte of interest is inserted into the light path, some of the energy will be absorbed, which will be proportionate to the amount of material present.  (Increasing the amount of material will absorb more energy, decreasing the amount of material will absorb less energy.)\n\nBy comparing the unknown material to a series of samples prepared in known concentrations, you can determine the concentration (amount) of the unknow sample.  The actual formula for this process is known as the Beer-Lambert Law.
42811
http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/D-Dyeing_vat-e.htm\n\nFound by simple web search