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Some basic concepts of chem

  1. Mar 14, 2005 #1
    1. What is the use of deflagrating spoon?
    2. What is the difference between copper (II) sulphide and copper (III) sulphide? (I don't understand what the II, III or IV mean)
    3. What is the term for the converse of sublimation?

    thanks
     
  2. jcsd
  3. Mar 14, 2005 #2

    Gokul43201

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    1. For safely combusting/reacting stuff that usually produces a lot of heat. So if you were to burn phosphorus or dunk sodium in water, you might want to use a DS. The long handle keeps you safely far from the nasty end.

    2. Google or look up oxidation states. This is a big topic and can not be answered briefly.

    3. Condensation or freezing - either can be used, even for going from gas to solid. Not sure if there's a more specific term.
     
  4. Mar 14, 2005 #3

    dextercioby

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    Copper has ON ony +1 and +2...At least pick a correct example.Nitrogen is very interesting,from this perspective.

    Daniel.
     
  5. Mar 14, 2005 #4
    Technically, the opposite of sublimation, the process of going from a gas to a solid is decomposition.
     
  6. Mar 14, 2005 #5

    Borek

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    While my English is limited I don;t think so. Decomposition is to separate or resolve into constituent parts or elements; disintegrate - it has nothing to do with the process opposite to sublimation.

    In some languages process the OP asked for is called "resublimation" but it seems this term is not used in English.
     
    Last edited by a moderator: Aug 13, 2013
  7. Mar 14, 2005 #6
    My apologies, it's Deposition
     
  8. Mar 15, 2005 #7
    soo.. what is the difference between (II) and (III)?
     
  9. Mar 15, 2005 #8

    dextercioby

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    One electron...?You're referring to ions,right...?Then,it's one electron.

    Daniel.

    P.S.Be more specific.
     
  10. Mar 15, 2005 #9
    In short, it stands for the charge of a transition metal cation.

    Many transition elements can form different types of cations. This has to due with the d sublevel of electrons. For example, copper normally can form Cu+ and Cu+2. You mentioned the Copper (III) ion. The Cu+3 ion is extremely unstable (i think it only lasts for about 5 seconds in solution) and therefore Copper (III) compunds do not exist under normal conditions. Copper (I) and Copper (II) do exist though like...Copper (I) Sulfate and Copper (II) Sulfate:

    Copper (I) Sulfate: Cu+ SO4-2 Therefore, Cu2SO4
    Copper (II) Sulfate: Cu+2 SO4-2 Therefore, CuSO4

    You also may encounter an older system of naming with the -ous suffix for the lesser ion and the -ic suffix for the greater one. So Cu2SO4 and CuSO4 are also known as Cuprous Sulfate and Cupric Sulfate, respectively.
     
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