CHM1205 - Lecture 1 & 2 - Laws of Thermodynamics (2020-21)

What is the main focus of Physical Chemistry?

The study of underlying principles that govern the behavior of chemical systems.

What does the First Law of Thermodynamics state?

Energy cannot be created or destroyed, only converted from one form to another.

What is Enthalpy?

A measure of the heat content of a system under constant pressure, represented by the symbol H.

Define the Standard Enthalpy of Reaction.

The heat change occurring at constant pressure when reactants are transformed to products at 298K and 1 atm.

What is the Zeroth Law of Thermodynamics?

If two systems are in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.

According to the Second Law of Thermodynamics, what happens to entropy in a spontaneous process?

The entropy of an isolated system tends to increase over time.

What is the criteria for a spontaneous process based on the changes in entropy?

For a spontaneous process to occur, the change in entropy of the universe must be greater than zero.

What does the symbol S represent in thermodynamics?

Entropy, which is a measure of the randomness or disorder of a system.

What is the importance of Physical Chemistry?

Helps understand the reasons for chemical changes, predict changes, and manipulate conditions to favor desirable changes.

What is the Third Law of Thermodynamics?

The entropy of a perfect crystalline substance approaches zero as its temperature approaches absolute zero.

How is the standard molar enthalpy of formation defined?

It is the enthalpy change when one mole of a compound is formed from its elements at 1 atm and 298K.

What happens to the total entropy in an organism as it grows?

While living things can increase order within their systems, the total entropy of the system and surroundings always increases.

What equation describes the relationship of entropy in a spontaneous process?

ΔSuniverse = ΔSsystem + ΔSsurroundings > 0.

How can we determine the spontaneity of a process?

By knowing the changes in both enthalpy and entropy of the system.

What is a common example of a spontaneous process?

The melting of ice at room temperature (H2O(s) → H2O(l)).