Thermochemistry/Thermodynamics Flashcards
System v. Surroundings
System is what we’re observing while the surroundings is everything else.
Describe the three types of systems.
- Open systems- System exchanges energy ( heat or work) and matter with surroundings.
- Closed Systems- System exchanges energy ( heat or work) but not matter with surroundings.
- Isolated systems- system cannot exchange energy ( heat or work) nor matter with surroundings.
Isothermal process
When a change in the system is characterized by constant temperature this changes the equation for the 1st law of thermodynamics to Q=W.
Process
When a system undergoes a change
Adiabatic process
They system does not exchange heat with the surroundings. Change in the internal energy of a system is equal to the work done by the system.
Isobaric process
System contains a constant pressure. Does not change the 1st law of thermodynamics equation.
Isovolumetric process
The volume of the system does not change. Because the volume doesn’t change there’s no work done on the object and therefore there’s no area under the PV graph.
What’s the equation that represents the change in internal energy of a system?
U = Q - W, where Q is the heat added to the system and W is the work done by the system.
Spontaneous v. Nonspontaneous reactions
Spontaneous reactions happens without the input of energy. Nonspontaneous reactions requires input of energy.
Spontaneous reactions doesn’t necessarily mean quick, only catalysts make them quicker.
How can we drive nonspontaneous reactions?
We couple them with spontaneous reactions.
State function v. Process function
State function describes a system’s equilibrium state. The process function describes how the system moves from one equilibrium state to another.
What are the standard conditions?
298K, 1 atm, 1M concentration
What does it mean when we say elements are in their standard states?
They’re in their most stable form
Phase diagrams
Shows the equilibriums and phase stages at different temperatures and pressures.
Vapor pressure
The pressure exerted by gas molecules at the surface of a liquid undergoing evaporation.
Evaporation
When liquid molecules gain enough KE to move into the gaseous phase.