4E.5

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How do you solve these types of problems?

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Okay so you can draw the Lewis structure and count how many bonds the structure has. For example, CH4 has 4 bonds because 4 H’s are bonded to one carbon. So you multiply the bond amount by the given bond enthalpy in the chart, you do the same thing for the rest and you add everything on the reactant side but subtract for the product side. Why subtract for the product side? Because energy is RELEASED to form bonds (exothermic, -).

BUT for example if it was 4CH4, then you would have to draw FOUR CH4 Lewis structures and count the amount of bonds. Therefore you would have a total of 16 bonds, and multiply the bond enthalpy for CH by 16!