CAIE A Level Chemistry 9701 · Chemical energetics

Chemical energetics: compare question

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The standard enthalpy change for the hydration of ethene, $\ce{C2H4(g) + H2O(l) -> C2H5OH(l)}$ , can be determined using Hess's law in two ways.

Way 1: Using standard enthalpies of formation of $\ce{C2H4(g)}$ , $\ce{H2O(l)}$ and $\ce{C2H5OH(l)}$ .

Way 2: Using standard enthalpies of combustion of $\ce{C2H4(g)}$ , $\ce{C2H5OH(l)}$ and $\ce{H2(g)}$ .

Compare the two ways in terms of the construction of the energy cycles involved. Do not include any numerical calculations.

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Chemical energetics: compare question

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