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Br2(l) --> 2Br(g)

Posted: Sun Jan 26, 2020 12:21 pm
by Amy Kumar 1I
For the reaction Br2(l) --> 2Br(g), how do you know which phase change enthalpies to use (why is it delta h vap + delta h bond)?

Re: Br2(l) --> 2Br(g)

Posted: Sun Jan 26, 2020 12:36 pm
by JonathanS 1H
We know to use the phase change from a liquid to gas, Hvap because that is what is demonstrated in the equation. We then use the H for breaking bonds because the Br2 becomes 2Br.

Re: Br2(l) --> 2Br(g)

Posted: Sun Jan 26, 2020 12:41 pm
by Tyler Angtuaco 1G
You use the heat/enthalpy of vaporization since the reactant is being vaporized into gas. You use bond enthalpy since the bond in the diatomic molecule Br2 breaks, forming two bromine atoms in the reaction.