6.1.3 The First Law of Thermodynamics Flashcards
The First Law of Thermodynamics
- The first law of thermodynamics states that total energy of the universe is constant.
- State functions depend only on the current state of a system, not how that state was reached.
note
- The first law of thermodynamics states that energy in the universe is neither created nor destroyed; it just moves around and changes forms.
- E = q + w means that the change in energy ( E)in a system equals the heat (q) produced in the system added to the work (w) done by the system on its surroundings.
- Heat or work may be done on a system (+) by its surroundings or may be done upon the surroundings by the system (-). However, the total energy of the system plus the surroundings is constant.
- The value of a state function does not depend on how a state was reached nor on the path or sequence of events that resulted in reaching that value.
- State functions include the internal energy, volume,
pressure, temperature, enthalpy, entropy (disorder), and
altitude of a system. - Factors that are not state functions include heat (q) and work (w).
In thermodynamics, what is the system?
The part of the universe being studied
In the equation E = q + w, what does the q represent
heat
What is heat?
a form of energy
What is the First Law of Thermodynamics?
The total energy in the universe is constant.
In the equation E = q + w, which of the following is (are) a state function(s)
E
Which non-state function increases as 1 mole of gasoline is burned in an internal combustion engine as opposed to burning 1 mole of gasoline burning in an open container?
the work
In the equation E = q + w, which of the following is NOT a state function
heat
What is a state function?
a property of the system that depends only on its present state
What is the definition of a law in science?
It is a statement or a mathematical equation that describes reality with no exceptions.
Which of the following is not a state function?
work
