Unit 3 Flashcards
What is energy
The capacity to do work or produce heat
Where is potential energy stored
stored in bonds
What is thermal energy
total amount of kinetic energy in a system measured in joules
What is heat and its symbol
thermal energy transferred between two systems symbol is q
What is heat capacity and its symbol
amount of heating necessary to change the temperature of an object (depends on the amount of stuff) symbol is C
What is specific heat and its symbol
heat capacity per gram symbol is c
What is enthalpy and its symbol
thermal energy absorbed or released by a system that is free to do work symbol is H
What is enthalpy when the rxn is exothermic and endothermic
negative for exothermic and positive for endothermic
What is a stipulation of the enthalpy of formation
element being calculated needs to be only one mol so others might be in fractions
What is the standard enthalpy of formation of elements in their natural state
zero
What is bond energy and its symbol
the energy required to break a bond symbol is D
What type of bonds are usually shorter
Stonger bonds
What types of bonds are stonger
triple bonds then double then single
What is lattice energy and its symbol
e required to pull ions apart symbol is delta H sub latt
What is entropy and its symbol
disorder within a system symbol is s
When is entropy favored or disfavored
when entropy is potive it is favored when its negative its disfavored
What is free energy and its symbol
maximum amount of work a system can do spontaneously symbol is G
What will free energy be when a reaction is spontaneous and not spontaneous
when negative the rxn is spontaneous and when postive the rxn is not spontaneous
When enthalpy is negative and entropy is positive what will free energy be?
negative
When enthalpy is positive and entropy is negative what will free energy be?
positve
Under what conditions does free energy depend on temperature
when enthalpy and entropy are both negative and positive
When an endothermic reaction occurs, what bonds are broken and what ones occur?
Strong bonds are broken while weak ones form
When an exothermic reaction occurs what bonds are broken and what ones occur?
Weak bonds are broken while strong ones form
When do molecules have a greater freedom of movement?
when pressure decreases
What is the kinetic theory
Gas particles are in constant, random motion. Pressure is a result of gas particles colliding with walls of a container. Volume of the gas particles themselves is assumed to be negligable. Gas particles are neither attracted to nor repelled by each other. The average kinetic energy of a sample of gas particles is proportional to temperature.
What is velocity dependent on and what are their relationships
temperature increases as velocity does and molar mass increases as velocity decreases
What is kinetic enegy dependent on and what is its relationship
temperature increases as kinetic energy does
What is the mean free path
distance that a gas particle travels before hitting another gas particle
What is diffusion
mixing of gases
What is effusion
rate at which gases expand into a vacuum through a small hole
When do real gases deviate from ideal behavior and why
At high pressure since as pressure increases, the volume of a gas particle becomes more significant thus, moving away from the ideal gas law. Low temperature since gas particles are attracted to each other but at low temperatures, particle attraction slows down thus, decreasing pressure which is not ideal
When work is negative and positve is work being done by or on the system?
When work is negative, work is being done by the system. When work is positive, work is being done on the system
What must delta V be in order for work to be negative
positive
What must delta V be in order for work to be positive
negative
When a rxn is endothermic what are the enthalpy and heat signs
positive and positive
When a rxn is exothermic what are the enthalpy and heat signs
negative and negative
What is the lattice energy trend
increases up and to the right
