Concepts In Chemistry - Physical Chemistry Flashcards
What is thermodynamics?
The study of heat and temperature and their relation to energy and work.
What is a system in thermodynamics?
The part of the universe we are interested in studying.
What are surroundings in thermodynamics?
The rest of the universe outside the system.
What is an isolated system?
No exchange of energy or matter with the surroundings.
What is an open system?
Freely exchanges energy and matter with the surroundings.
What is a closed system?
Exchanges only energy with the surroundings, not matter.
List the four quantities expressed in thermodynamics.
- Temperature (T)
- Internal Energy (U or E)
- Entropy (S)
- Heat (Q)
Define extensive properties.
Properties that depend on the amount of matter present in a system.
Define intensive properties.
Properties that do not depend on the amount of matter present.
What is a state function?
A property that depends only on the current state of the system.
What is a path function?
A property that depends on the path by which the system achieved a particular state.
What does the Zeroth Law of Thermodynamics state?
If object A is in thermal equilibrium with object C, and object B is in thermal equilibrium with object C, then A and B are in thermal equilibrium.
What is heat in thermodynamics?
The process of energy transfer due to thermal contact.
What is the formula for internal energy change in terms of heat?
ΔU = q
What is an exothermic process?
A process that releases heat into the surroundings.
What is an endothermic process?
A process that absorbs heat from the surroundings.
What is heat capacity?
The ratio of the heat supplied to the rise in temperature observed.
What does the Ideal Gas Law describe?
The relationship between pressure, volume, temperature, and the amount of gas.
What is the formula for the Ideal Gas Law?
PV = nRT
What is work in thermodynamics?
The energy transferred by the system to its surroundings.
What is the formula for the first law of thermodynamics?
ΔU = Q + W
What is specific heat?
The energy required to increase the temperature of 1 unit of a substance by 1 degree.
True or False: Internal energy is independent of the path taken to reach that state.
True
Fill in the blank: The energy transferred as heat is labeled ______.
q
What is the formula for the change in internal energy (ΔU) related to heat (Q) and work (W)?
ΔU = Q + W or ΔU = Q − W
What does the equation ΔU = Q + W assume about work (W)?
W represents the work done on the system
What does the equation ΔU = Q − W assume about work (W)?
W represents the work done by the system
True or False: The equations ΔU = Q + W and ΔU = Q − W are equivalent.
True
When work is done on a system, how does it affect the internal energy of the system?
It adds to the internal energy of the system
When work is done by a system, how does it affect the internal energy of the system?
It takes away from the internal energy of the system
Define work (W).
Work is motion against an opposing force
Define heat (Q).
Heat is the energy transferred as a result of a temperature difference
Define energy (U).
The energy of a system is its capacity to do work
What symbols are used to signify ‘change in’?
d and Δ
What does ΔV represent?
Change in volume
Fill in the blank: Work done on a system is represented by _______.
W on gas
Fill in the blank: Work done by a system is represented by _______.
W by gas
In which textbook can you find more information on energy and chemistry?
Atkins’ Physical Chemistry
What is the significance of keeping track of the signs of Q and W?
It is vital for applying the first law of thermodynamics correctly
