Recent content by sven222

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    Concentrations/ mixing

    C1V1 = C2V2
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    Effect of pH changes on UV absorbance

    OK well I thought I had the answer, but some complications have arisen. In the next part of the question, you needed to find the molecular weight of the phenol compound by calculating concentration through absorbance etc etc. So anyway, I worked out a molecular weight of 158, which is...
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    Effect of pH changes on UV absorbance

    Ah, you're my hero! :biggrin: I knew there was a simple mistake I was making, that in turn ruined the rest of my workings. I must admit it has been some time since I studied equilibrium, so the french guys principle wasn't exactly slapping mei n the face. But it all makes sense now :smile...
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    Effect of pH changes on UV absorbance

    So I have an chem assignment which i've been going through for the past week or so, but the last question has provided somewhat of a stumbling block. Here it is, So from the question, I have gathered the following, High pH solutions absorb at higher wavelenghts. Whereas low pH solutions...
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    Factoring dilutions into calculations

    Thanks for the reply iansmith, greatly appreciated. Firstly, wouldn't the net A260 be sample - blank? Rather than blank - sample? And when you say DNA constance, I assume you're referring to the 50ug/ml I mentioned above. Besides that, I didn't realise it was that simple. It must be the...
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    Factoring dilutions into calculations

    Hey guys, gals (Monique :wink: ) Quick question. I recently completed a labortatory session in my Genetics class regarding the isolation and analysis of plasmid DNA, and a section of the report has me stumped. Before the plasmid DNA was put under the spectrophotometer, it was diluted in...
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    Why do I never see anything made out of a lithium compound?

    Both lithium metal and its compounds have many uses. lithium stearate is mixed with oils to make all-purpose and high-temperature lubricants lithium hydroxide is used to absorb carbon dioxide in space vehicles lithium is alloyed with aluminium, copper, manganese, and cadmium to make...
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    Classifying reaction type

    It's a decomposition reaction because the main reactent is decomposed into its components. However I can also see why you think it would be a combustion reaction. Maybe it can be both? Someone else may be able to shed more light on the problem.
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    The Nobel Prize in Chemistry 2003

    I don't see why you would/should be jealous. The fact that you worked with these men alone should be enough. Plus it would look awesome on your resume
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    Chemistry Diee !

    The question didnt really give enough info. I was assuming it meant Cl gas, in which case it is Cl2. It may have meant Cl in the ionic form however, in which case you would be correct. From the info he gave though, it sounds as if it is meant to be in the gas, or Cl2, form. And also, he has Cl2...
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    Math Rules Chem

    Is there a point to this thread?
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    Chemistry Diee !

    Al has a 3+ charge because in order to get into the nearest noble gas configuration (1s2, 2s2, 2p6), it needs to lose 3 electrons. Theoretically it could indeed have a 4+ charge, but it would not be energetically favourable, therefore it is not likely to occur under normal conditions.
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    How do you improve chemistry?

    During first year Molecular Bio, I often woke up in a cold sweat from ETC/OP/Citric nightmares
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    Chemistry Diee !

    The equation for the reaction between Cl2 and Al is as follows, 3Cl2 + 2Al ---> 2AlCl3 (Ionic, Al has a 3+ charge, and Cl has a 1- charge) So 3 moles of Cl2 will react to produce 2 moles of AlCl3. Therefore if 5 mol of Cl2 is used to begin with, 3.33333 (10/3) mol of AlCl3 will be...
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    How do you improve chemistry?

    Chemistry is the central science. Love it, and it will love you back :smile:
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