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Chemical energetics question

Given S(s) + O2(g) SO2(g), ΔH formation = –297 kJ mol–1
and S(s) + 1.5 O2(g) SO3(g) ΔH formation = –395 kJ mol–1
what is the enthalpy change of reaction, ΔH formation, of
2SO2(g) + O2(g) 2SO3(g)?
A –196 kJ mol–1
B –98 kJ mol–1
C +98 kJ mol–1
D +196 kJ mol–1
Work it out.
-196
Original post by Noorhasan
Can you please show a demonstration of the working?


2 x (SO2 => S + O2) = +594 [1]

2 x (S + 1.5O2 => SO3) = - 790 [2]

[1] + [2] = 2SO2 + O2 => 2SO3
-790 + 594 = -196kJmol^-1
Reply 4
Original post by The Wavefunction
2 x (SO2 => S + O2) = +594 [1]

2 x (S + 1.5O2 => SO3) = - 790 [2]

[1] + [2] = 2SO2 + O2 => 2SO3
-790 + 594 = -196kJmol^-1


I deleted my message to you as soon as I got the answer, thanks anyways! I just forgot to multiply the SO3 with 2. c:

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