Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: PolloChief on June 01, 2021, 03:02:28 PM
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The question is this:
CaCO3+179.2KJ --->CaO (s)+ O2 (g)
A) The reaction is spontaneous in high temperatures.
B) The reaction is spontaneous in Low temperatures.
C) Is always spontaneous.
D) Is always Non-spontaneous.
I chose option A, but can't find the answer in my textbook.
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What is the relationship between Gibbs free energy and spontaneity? How would you calculate it?
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∆G=∆H-T∆S
∆H is Enthalpy
T is temperature
∆S is Entropy (or change in entropy).
In this question, entropy is (+) because the product has more moles and a change in state (s-->g).
But I don't know if ∆H is (+) or (-).
If ∆G=+
Then it's Non-spontaneous.
If ∆G=-
Then it's spontaneous.
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But I don't know if ∆H is (+) or (-).
CaCO3 + 179.2 kJ ---> CaO (s)+ CO2 (g)
Positive enthalpy means that reaction consumes heat, negative - heat is emmited.
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Yeah I know that much, it's just that I don't know if this reaction is consuming or emitting heat.
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Yeah I know that much, it's just that I don't know if this reaction is consuming or emitting heat.
Do you see a difference between
A + 100kJ :rarrow: B
and
A :rarrow: B + 100kJ
?
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I get confused on which is which everytime when I see the KJ in the reaction. So I'm not sure.
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Heat is either on the left (consumed) or on the right - produced.