Calculate the heat change at 100C in each of the following problems.Indicate whether heat was absorbed or released.
a. calories to condense 10.0 g of steam
b. kilocalories to condense 75g of steam
c. kilocalories to vaporize 44 g of water.

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  1. a.
    q = mass steam x delta Hvap.
    see a. Convert to kcal.
    mass H2O x deltaH vap. Convert to kcal.

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  2. a. 12

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  3. First you multiply 10.0 with 540cal/1 g of H2O.

    To calculate the amount of heat added to (or removed from) a sample of water, the mass of the sample is mulitipled by the heat of vaporization, which is 2260. As before, no temperature change occurs during a change of state.

    the answer for a will be 5400

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