Question about the rules of thermodynamics

Click For Summary
SUMMARY

The discussion centers on the relationship between standard enthalpy change (ΔHr °) and standard heat of formation (ΔHf °) in thermodynamics. It establishes that ΔHf ° equals ΔHr ° for reactions forming one mole of a compound from its pure elements in their most stable state at standard conditions. The participant confirms that this principle also applies when calculating standard Gibbs free energy change (ΔGr °) using standard Gibbs free energy of formation (ΔGf °).

PREREQUISITES
  • Understanding of thermodynamic principles, specifically ΔHf ° and ΔHr °.
  • Familiarity with standard state conditions in thermodynamics.
  • Knowledge of Gibbs free energy and its significance in chemical reactions.
  • Basic skills in chemical reaction stoichiometry.
NEXT STEPS
  • Study the relationship between ΔGr ° and ΔGf ° in detail.
  • Explore the implications of standard state conditions on thermodynamic calculations.
  • Learn about Hess's Law and its application in thermodynamic calculations.
  • Investigate the role of Gibbs free energy in predicting reaction spontaneity.
USEFUL FOR

Chemistry students, educators, and professionals in fields requiring thermodynamic analysis, particularly those focusing on reaction energetics and equilibrium.

samy4408
Messages
62
Reaction score
9
Hello , we learned in thermodynamics that to calculate ΔHr °(of the reaction ) using ΔHf °(standard heat of formation ), we have to respect that
ΔHf °=ΔHr ° of a reaction forming 1 mol of compound from pure elements in their most stable form at standard state .
the problem is when we want to calculate ΔGr ° using ΔGf ° is it necessary to respect the rule raised before ?
thanks .
 
Science news on Phys.org
Yes.
 
Reply
  • Like
Likes   Reactions: Mayhem, samy4408, Bystander and 1 other person

Similar threads

Undergrad Minimization of the Gibbs energy when number of molecules varies
  • · Replies 16 ·
Replies
16
Views
3K
Graduate Understanding Enthalpy: Confusion Cleared Up | Thermodynamics Course"
  • · Replies 14 ·
Replies
14
Views
3K
Graduate Thermodynamics: Enthelpy vs. Gibbs Free Energy usage
  • · Replies 9 ·
Replies
9
Views
3K
Thermodynamics Question Regarding Gibbs Free Energy, Enthalpy, Entropy
  • · Replies 1 ·
Replies
1
Views
2K
Chemistry A calculation of enthalpy, entropy, and Gibbs energy of vaporization
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad A paradox about energy balance and steady state
  • · Replies 2 ·
Replies
2
Views
2K
Thermodynamics of chemical reactions
  • · Replies 28 ·
Replies
28
Views
3K
Graduate Why is Qir < than Qr? Carnot cycle and change in G
  • · Replies 34 ·
2
Replies
34
Views
4K
Undergrad Calculating Gibbs Free Energy w/o Standard Entropy
  • · Replies 4 ·
Replies
4
Views
2K
Graduate Question about Gibbs free energy from Kubos' Thermodynamics
  • · Replies 10 ·
Replies
10
Views
2K