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Homework Help: Energy change to form KI(s)

  1. Oct 14, 2006 #1
    Hello all I just need to know if the procedure I'm taking is right.

    I need to find energy change of 1.05 Mol of KI(s) given that:

    I2(s) → I2(g) : 62.44 KJ/mol
    K(s) → K(g) : 180.4 KJ/mol
    1/2 I2(g) → I(g) : 138.05 KJ/mol
    K+(g) + e− → K(g) : −419 KJ/mol
    I−(g) → I(g) + e− : 295.16 KJ/mol
    Lattice energy for KI = −649 KJ/mol

    I tried adding all the values and then multiplying by 1.05 mol but that doesn't seem to work so then what I did was multiply 1.05 by the lattice energy and then add up all the values but I still am not getting the correct answer. There is a diagram in my text and I followed every step yet am I doing something wrong?
  2. jcsd
  3. Oct 23, 2016 #2


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    Check the iodine stoichiometry.
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