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Balancing chemical equations

  1. Dec 11, 2011 #1
    I was practicing some balancing chemical equations for a chemistry test, and I noticed this:
    Cu(NO3)2 (numbers are subscripts.)

    I've never seen parenthesis in a chemical formula before, no clue what it means. Nothing in my text books, and I can't really ask the teacher since the test is tomorrow.

    The equation was in my book, so its not going to be something I have yet to learn.

    Here's the full, unbalanced equation.

    Cu + AgNO3 ----> Cu(NO3)2 + Ag

    Sorry if this is a really stupid question, i don't know much about chemistry (i know what i learn in class.)
    Last edited by a moderator: Dec 11, 2011
  2. jcsd
  3. Dec 11, 2011 #2

    Simon Bridge

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    Re: Silly Question

    It means that the entire molecular ion inside the parentheses appears twice, as in:

    NO3- -- Cu2+ -- NO3-
  4. Dec 11, 2011 #3


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    Re: Silly Question

    It basically means that there are two of the chemical species within the parentheses. Cu(NO3)2 means that the substance has two NO3- ions for every one Cu2+ ion. You could very well write this as CuN2O6, but keeping it written as Cu(NO3)2 helps to emphasize that it consists of Cu2+ and NO3- ions.
  5. Dec 13, 2011 #4
    Okay, thanks.
  6. Dec 25, 2011 #5
    And also Cu(NO3)2....Cu^2+ and NO3 ^-1, remember the charges come down, so that's how you get Cu1(NO3)2
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