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Homework Help: Mass lost in chemical reactions?

  1. Apr 12, 2010 #1


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    1. The problem statement, all variables and given/known data

    In chemical reactions, when energy is released, mass is lost according to Einstein’s formula just as it is for nuclear energy (though the amounts lost are so small that for centuries scientists thought that mass was conserved). When a kilogram of coal is burned, it releases about 40 million joules of energy.

    a. What amount of mass is lost?
    b. How many carbon atoms would it take to match the amount of mass that is lost?

    2. Relevant equations

    mass = 2.0 × 10- 26 kg
    1H + Energy n + e+ + v ----> is this a formula that needs to be used?

    3. The attempt at a solution

    I am so lost...:( can anyone help!?
  2. jcsd
  3. Apr 13, 2010 #2


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    Homework Helper

    How is energy and mass related? You certainly remember Einstein's famous equation.

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