Recent content by duke656

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    Slow precipitation of calcium carbonate.

    Thank you Borek, I will try it.
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    Slow precipitation of calcium carbonate.

    Hello Everyone, I am working with CaCO3. I want to have the precipitated CaCO3 in the laboratory. The easy way is to mix Na2CO3 and CaCl2. It gives CaCO3 and NaCl but this reaction takes place in a flash. As the reaction rate is high the produced CaCO3 forms powder like substance (the syze of...
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    What is the Correct Method for Measuring CO2 Gas Volume?

    Thank you all. This problem is solved by reducing the volume of acid at the same time increasing it`s concentration. I am very thankful to you all.
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    What is the Correct Method for Measuring CO2 Gas Volume?

    Bystander, let me describe my apparatus. I used a 500 mL conical flask with a air tight rubber stopper (cork). The stopper has two holes in which stopper funnel and tube for gas collection is inserted. The collection tube is a brass tube that directly goes into the water filled measuring...
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    What is the Correct Method for Measuring CO2 Gas Volume?

    I have done the similar experiments for 0.1, 0.2, 0.3, 0.4 and 0.5 g of CaCO3. The amount of gas collected is also nearly 30, 60, 90 120 and 150 cc respectively. Bystander, I used 30 ml of 2.0 mol/L HCl. It is more than enough to completely neutralize the used amount of CaCO3. Is there any...
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    What is the Correct Method for Measuring CO2 Gas Volume?

    Thank you Borek. I also conducted the similar experiments using commercial calcium carbonate. Every time the amount of CO2 gas is around 25% more than the theoretical value. Are there any other causes of positive error? Thanks in advance.
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    What is the Correct Method for Measuring CO2 Gas Volume?

    Hi! I am trying to evaluate the amount of CO2 gas produced from the reaction of CaCO3 and HCl. Theoretically the amount of gas that can be achieved from the 0.1 g of calcite is around 24 cc (T=21 degree and P is 1010 mb). But, the experimental value that I obtained is around 30 cc. I have no...
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    Which crystal dissolves in only hot water and recrystalize on cooling

    Borek and Jim thank you. I am looking for something like Borek wrote. Could you share some idea Borek? Let me describe my problem. Say, I have a sack full of glass beads (0.5 mm). I would like to inject the chemical in the form of solution(dissolved in hot water). I want this solution to...
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    Which crystal dissolves in only hot water and recrystalize on cooling

    Dear all! Somebody, please tell me which crystal is soluble in hot water but not in cold water. I am looking for some crystalline chemicals which are strong enough to bind something like glass beads. As I mentioned, it should be highly soluble in hot water (or change into liquid on high...
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    Measurement of concentration of urea

    Probably, I could not make you understand. Let me start from the beginning. I have some water samples obtained from the sandy soil. They are a bit turbid and contain urea in higher concentrations (more than 0.5 mol/L). I would like to evaluate the concentrations of only urea of each of these...
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    Measurement of concentration of urea

    Thank you Borek. Will this method work if there is some impurities other than urea? For example I will inject 0.5 M urea into one end of a 1 m long tube full of sand. Then I collect samples from the other end and try to evaluate the concentration. Thanks in advance. Peace Deb
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    Measurement of concentration of urea

    Dear All Does anyone have any idea about how to determine the concentration of liquid urea. The concentration is a bit higher (0.5-1.5 mol/L). Is there any laboratory techniques or Kit? I looked for and found everywhere the method to measure the amount of urea in blood and urea but what I want...
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    What may be the negative catalyst?

    Can you please suggest me what may be the probable thickeners? Is it sodium polyacrylate? or sodium alginate or gums. Thanks in advance Peace Deb
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    What may be the negative catalyst?

    Thank yo very much aroc91 and chemisttree. I once tried by lowering the temperature. It did not work actually, probably because I want to mix higher concentration say 0.5 molar solution. I will follow the suggestion of chemisttree and let you know. If you have other ideas please share with me...
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    What may be the negative catalyst?

    The reaction between sodium carbonate and calcium chloride gives the table salt and calcium carbonate. The reaction takes place immediately after mixing two solutions. Can anyone suggest me how the reaction can be slowed down? Thank in advance Peace Deb
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