Thermodynamics Propeeties

Question 1

Spontaneous process

Answer 1

-refers to how it occurs on its
own without the help of any external factors.
Example: A hot cup of coffee will turn cold.

Question 2

Non-spontaneous process

Answer 2

• will not take place unless it
  is “driven” by the continual input of energy from an
  external source.
  Example: A plant absorbs water and carbon dioxide. But
  for it to get converted, sunlight is required.

Question 3

Entropy

Answer 3

a measure of the disorder of a system.
It also describes how much energy is not available
to do work. The more disordered a system and higher
it is, the less of a system’s energy is available to
do work.

Question 4

4 factors that influence entropy

Answer 4

CTIP

Question 5

Change in temperature

Answer 5

– raising the temperature
of a system increases the average kinetic energy
and the freedom of motion of the particles in the
system resulting to an increase in entropy.

Question 6

Third Law of Thermodynamics

Answer 6

states that a
perfectly ordered pure crystalline solid at zero
Kelvin will have zero entropy.

Question 7

Increase in the number of particles

Answer 7

lead to more
disorder in the system and that increases the
entropy.

Question 8

Phase changes

Answer 8

– as the boiling point of a substance
(solid, liquid, gas) is reached, entropy also increases.

Question 9

Standard Molar Entropy (S°)

Answer 9

– is the entropy of one
mole of a substance at the standard conditions (1 atm
and 25°C).

Question 10

Second Law of Thermodynamics

Answer 10

explains the
relationship between entropy change and spontaneity
of a process. It states that for any spontaneous process,
there is a net increase in the total entropy of the system
and its surroundings.

Question 11

This net entropy change of the
process is represented as ∆Suniv.

Answer 11

∆Suniv = [∆Ssys + ∆Ssurr] > 0

Question 12

Gibbs Free Energy and Spontaneity

Answer 12

From earlier discussions, the spontaneity of a process
depends on two thermodynamic quantities: enthalpy
and entropy. Combining these two into a single
equation introduces a third thermodynamic quantity
that ultimately determines spontaneity. This quantity is
referred to as the Gibbs free energy (G), named after
the American mathematician and physicist Josiah
Willard Gibbs. Free energy is a portion of the total
energy of a system that is available to do useful work.

Question 13

Gibbs free energy and sponteinty

Answer 13

∆G = ∆H – T∆S