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Homework Help: Chemistry help

  1. Jul 31, 2003 #1
    Chemistry help plz!!

    I've tried to work out the problem below, but I got weird answer, it's not even in one of the choices. Please help me solve this problem and show me out u got it. Thank you.
    A sample of a hydrate of BaCl2 with a mass of 61 grams was heated until all the water was removed. The sample was then weighed and found to have a mass of 52 grams. What is the formula for the hydrate?
    (A) BaCl2 * 5H2O
    (B) BaCl2 * 4H2O
    (C) BaCl2 * 3H2O
    (D) BaCl2 * 2H2O
    (E) BaCl2 * H2O
  2. jcsd
  3. Jul 31, 2003 #2
    show us what you did first
  4. Jul 31, 2003 #3
    Ba=137.3gtams Cl2=71 grams
    BaCl2=208.3 grams --> but the answer in book says BaCl2 =244 grams.
    61 grams - 52 grams = 9 grams
    9grams / 18grams (H2O) = 1/2
    so my answer is BaCl2 * 1/2 H2O, which doesn't make any sense @ all, and it's not one of the answer choices.
  5. Jul 31, 2003 #4
    ok so you have 1/2 moles of H20, how many moles of BaCl2 do you have? balance them out and you'll get the answer.
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