I have to do this for a science project, i have to write my own procedure and use Beers Law and find out if i can find the rate of the reaction by using a colorimeter.
213879
Ummm...You will have to figure out which is faster... but I can give an idea as to proceedure...First, try to answer this question: What are all the colored species in grape juice? You need to know that first. Hopefully there is only one. That would simplfy things. Then you need an extinction coefficient for that compound, if you can find one. Using that, you can take several absorbance measures and use Beer's law to establish the concentration of that species in your stock solution. Beer's law states that Absorbance = extinction coefficient x concentration x path length. Your path length is the width of your cuvette, which is usually 1 cm. Beer's Law will not be valid if you use a solution that is so concentrated that it gives you an absorbance value greater than 2. At Absorbance = 2, well over 99% of light is being absorbed. A reading over 2 is thus considered analytically unusable. Your juice can be diluted, if necessary, with DEIONIZED (aka distilled) water. Once you do that, I would roughly time each reaction by just looking at it with my eye, adding just a drop or so of bleach/peroxide initially, and increasing the amount only if necessary. Make sure to add exactly the same amount of bleach/peroxide to exactly the same volume of grape juice. Once you have the reaction basically set up to your satisfaction, then place your juice sample in the colorimeter and get ready to add your reagent. Remember to take a measurement before you add any bleach/peroxide for EACH of the two tests. And take your measurements on the same time frame (ex: every 30 sec.)Good Luck!!! :-)
97902
no, reaction times are too slow at that temperature.  (I'm just guessing, but I'm a chemist.  You should be able to look up reaction energies, try Beilstein.)
303853
try \n\ngtitestlaboratories.org
310261
2.\nBy decreasing the temperature and increasing the pressure. As ussually done in Haber;s process\nAnother way is to keep on removing the ammmonia gas to make reaction go forward\nRead th Le Chatelier's principle for more detail.\n\n13.\n2 HCl + Na2CO3  -----> 2 NaCl + H2CO3\nH2Co3 can exist as water and carbon dioxide.\n\n14.\nBecause acid-base reaction is spontaneous.\n\n11.\nBecause of the formation of copper(II) carbonate which will settle down as precipitate.
431964
1) This is basically the application of Gay Lussac's Law of combining volumes and Avogadro's Law. We know 8.53 grams of BaCl2 is reacting, so calculate the molar mass of BaCl2, and thus find the volume that 8.53 grams occupy. Then using Gay Lussac's Law, find the volume of KCl. Now, find the molar mass of KCl, and since you know the volume, you will be able to find out the number of KCl that is produced. \n\n2) For this reaction, the increase of temperature will speed up the reaction as increasing the reactants unequally will not result in a faster reaction.
551990
ok--i'm not completely sure about this--but i can at least try-- *cough cough*unlike some people*cough*cough*catweazle*\n\nwe did this type of stuff last year.  but i think that you might want to use the ideal gas law?? we always called it pervnert... PV=nRT... does this sound familiar?    \n\nif not, i suggest asking your teacher, or some other knowledgable chemistry person.\n\ni hope this helps!
230262
inorder to verify whether the given soln is acid or base , we need to perform litmus paper test\n\nan acid soln converts red litmus paper to blue when it is poured on it\n\nsimilarly 4 base
210338
did you also prepare a standard solution? because the way i do it, is that i have a standard so i can compare the 2 absorbtions (same wavelength)...You know the equation..
493549
I was confused by your question at first, but I think I understand if you're currently studying kinetics.\n\nThe rate of a reaction can be expressed in a rate law such as: \n Rate = k[concentration]^n.\nIn that equation, k is the rate constant and n is order of the reaction.  A second order rate law would have the form: \nRate = k[ ]^2.   \n\nAlthough they're less talked about in general chemistry, a reaction order could be negative.  (This just would mean you'd have a negative value for n.)  For example, a rate law where n = -1 with respect to oxygen would look like:\n\nRate = k [O2]^-1 = k / [O2]\n\nTo try to verify this experimentally, you would need a method for monitoring the concentration of the oxygen during the reaction (or a different method for measuring it indirectly).  If you had a set of data points for how the concentration of O2 changes with time, you could make a graph with time on the x axis and the concentration of O2 SQUARED on the y axis.  If this graph was of a straight line, that would be experimental evidence that the order of the rate law with respect to O2 is indeed -1.
264363
Okay, I'll try this one -\n\nRun this experiment twice (or more times), each time with a piece of metal having different density.  The metal piece should be of adequate size (a sewing needle isn't going to do it), it needs to be big enough to significantly affect the temperature of the water.  You will need to know the mass of the metal (i.e., weigh it) and have a thermometer capable of reading from room temperature up through boiling or so.  Please note this is not going to give you a highly accurate answer, but can give you a ballpark idea (I'm guessing you're probably not doing this in a 500 million dollar lab).\n\nThe procedure:\n\n1)  Measure and record room temperature as T1.\n\n2)  Weigh the metal, call it M1.\n\n3)  Bring a known quantity of water (weigh it, or measure it and convert to weight, call it M2) to a temperature just short of boiling (say 180F to 200F, use the same temperature for each run of this experiment).  Record the temperature as T2, and remove the heat source (take it off the burner, etc.).\n\n4)  Drop in a metal piece at room temperature.  Allow a couple of minutes for heat to exchange.  Make sure you use \nthe same amount of time for each run of this experiment.\n\n5)  Measure and record the new temperature of the water as T3.\n\n6)  Repeat with your other metal samples.\n\nYou can now estimate the specific heat capacity for each metal.  It will not be super-accurate (heat escapes your system, and temperatures won't have completely equalized), but should give you some idea.  Just assume all temperatures did equalize and that no heat escaped for calculational purposes.\n\nSince (you are assuming) the heat which left the water went into the metal, then the product of mass, specific heat capacity, and temperature change should be the same for both the metal and the water (but in opposite directions).\n\nThis means that:\n\n(M1)(c1)(T3-T1) = (M2)(cw)(T2-T3)\n\nwhere c1 is the specific heat capacity of the metal, and cw is the specific heat capacity of water (look it up on Google to get the units you need).\n\nSolving this, you get:\n\n......(M2)(cw)(T2-T3)\nc1 = -----------------\n........(M1)(T3-T1)\n\n(sorry about the dots, I'm trying to keep everything aligned)\n\nRepeat the calculations for each of the metals.\n\nYou will need to calculate (or look up) the densities of each of the metals.  Then, graph density vs. the specific heat capacities you calculated, and see if your hypothesis is true.\n\nHave fun!
360694
To prevent the prepared Grignard reagent from hydrolyzing before it has a chance to react.\n\nThe Grignard reagent is prepared with R-Br\n\nR-Br + Mg --> R-MgBr\n\nThis is then usually reacted with a Carbonyl compound (C=O) and then hydrolyzed to the alcohol.  If water is present then:\n\nR-MgBr + H2O  -->  R-H  +  Mg+2  + Br-1  +  (OH)-1\n\nThis can also be written as:\n\nR-MgBr  +  H2O  -->  R-H  +  Mg(OH)Br
133697
yes, reaction rates are based on several things, concentration and temperature are the most important, because of the water added to the reaction, it will be less "likely" that a vinegar molecule will collide with a baking soda molecule, because of this the reaction will go slower. the way to calculate this is K = [Products]/[reactants].  Where [] is the concentration of each solute present (in moles per liter), and K is the constant value for this perticular reaction, which can be found in a chemistry text book.
40002
I think the only pratical way ot do this will be to distill the kerosene.\n\nBut be aware that you are probably breaking the law by doing so. The colouration is added to make it comply with safety laws.
354191
First off, you need the concentration of the NaOH solution.  From that you can determine the number of moles of NaOH that were used.  This is equal to volume (V) time the concentration, in mol/L (C).\nn = V * C = 0.02260 L * ? mol/L = ? mol\nn = 0.02200 L * ? mol/L = ? mol\n\nThe reaction of KHP (C8H5O4K) and NaOH is this:\nHOOC-C6H4-COOK + NaOH -> NaOOC-C6H4-COOK + H2O\nSo, 1 mol of NaOH will react with 1 mol of KHP.\nThat means that the number of moles of NaOH you calculated above is also equal to the number of moles of KHP.\nThe molecular weight of KHP is 12*8 + 1*5 + 16*4 + 39 = 204 g/mol\nMultiply that by the number of moles: 204 g/mol * ? mol = g actual KHP\n\nYou can divide that number by the 0.911 and 0.950 g and then multiply by 100% to find the purity.\n\nHere’s an example if your NaOH solution was 0.1 M (M means ‘molar,’ or mol/L):\nn = 0.02260 L * 0.1M = 0.002260 mol of NaOH = 0.002260 mol of KHP\n204 g/mol * 0.002260 mol of KHP = 0.461 g pure KHP\n0.461 g pure KHP / 0.911 g impure KHP * 100% = 50.6 % KHP\n\nHope this helps!
488217
"The final experiment was to observe the reaction when one small crystal of NH4SCN was added to 0.1 M FeCl3. The color of FeCl3 was yellow, but after NH4SCN was added, the color of contents changed to red.\nIn second experiment, when the Mg was ignited, the resulting flame was hot. Therefore, the release of thermal energy through the interaction of Mg and O was shown.\nFiguring out the type of the last two reactions was difficult, because the chemical equations were not given. However, the possibility that the type of both reactions were replacement reactions was high. The reason being that the chemical reactions were observed as a color change and this means that the composition of the substance is changed.\nThis experiment was very successful, and it was a good opportunity to observe chemical reactions directly."\n\nI would change your paragraph to that.  I would also expand on the other experiments if you know more about them.
410491
well theres alot of material i can provide you with but i dont know what particular experiment you are designing as there are always different experiments within an experiment.\nanyhow, i think this is an example of an experiment for photosynthesis and respiration and their pH levels.\n\nhttp://www.science.siu.edu/plant-biology/plb337/old_st_papers/emmert.pdf \n\n\nif you are doing the same experiment, i guess you will find this one really helpful.\n\n.. Good Luck
51199
Please do your own home work.\n\nI suspect you are missing a symbol, it probably should be,\nN2O4  <==>  2NO2\n\nThink about how each of the changes will effect the equilibrium of the reaction.