# Thermodynamics: Enthalpy and Entropy

1. Given that a formation of a bond between two atoms is exothermic and accompanied by an entropy decrease, explain why all chemical compounds decompose into individual atoms if heated to a high enough temperature.

2. Is the dissolution of urea driven by enthalpy or entropy? How do you know this? Give one example of each of a process that is driven by enthalpy, and one that is driven by entropy.

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Hello,

Question 1

The Gibb's free energy equation related to enthalpy and entropy is as follows:

G = H - TS

And if the change Gibb's free energy is less than zero or negative then a reaction will proceed spontaneously.

In the case of decomposition or bond-breaking which is endothermic the change in entropy will be positive due to the formation of more particles.

Therefore, in looking at the equation bond-breaking will be entropy driven: In other words ...

#### Solution Summary

This solution provides calculations and explanations for various thermodynamic concepts.