AP Chem Ch.6 - Definitions

*Note: SEPARATE flashcards for formulas! ... (***) = has a formula ! (•) = NOT a term used in AP Chem Exam

1st Law of Thermodynamics (Law of Energy Conservation) 

Energy cannot be created nor destroyed; only converted from one form to another! 

Energy lost by system = energy gained by surroundings (and vice versa)

2nd Law of Thermodynamics 

Entropy in the universe increases

3rd Law of Thermodynamics

Entropy of a perfect crystal (perfect order) is zero

Entropy of a system at absolute zero is zero

Adiabatic system ***

System in which there is no exchange of heat or mass between the system and surroundings; Energy is transferred to the surroundings only as work

Bomb Calorimeter ***

Calorimeter at constant volume

Calorimeter

Device used to study heat flow associated with a chemical reaction

Closed system

System that can exchange heat but not mass

Coffee cup calorimeter (OR constant pressure)

Calorimeter at constant pressure; used to study enthalpy changes for reactions in solutions 

Endergonic rxn •

Reaction that requires energy

Endothermic rxn

Rxn that absorbs heat: reactants + heat → products

Energy***

Ability to produce heat or work

(units: Joule, Calorie, calorie)

Enthalpy (H = q_p) ***

Heat at constant pressure 

Exergonic rxn •

Reaction that releases energy

Exothermic rxn

Reaction that releases heat: reactants → products + heat

Extensive Property

Property DEPENDENT on amount of matter (mass, volume, energy, enthalpy, heat, heat capacity, etc.)

Heat (q) ***

Energy transferred between objects at different temperatures

Units for heat: calorie, Joule, kilojoule

1 nutrition Calorie = 1000 chem calories = 1 chemistry kcal

Intensive Property

Property INDEPENDENT on amount of matter (temp, density, color, specific & molar heat capacity, etc.)

Isolated system

System which does not allow the transfer of heat and mass with the surroundings

Isothermal system (𝚫T = 0)

System at constant temperature

Kinetic energy ***

Energy due to motion

Matter

Anything that has mass and volume (takes up space)

Molar heat capacity (c) ***

Energy needed to raise the temperature of one mole of substance by one °C

Non-state function

Function is dependent on the process/path

Open System

System that can exchange mass and energy with the surroundings

Potential energy ***

Energy due to position

Specific heat capacity (s) ***

The energy needed to raise the temp of one gram of substance by one °C

Specific heat for water **

Specific heat capacity for water

State function

Property determined by the state of the system regardless of how the condition was achieved; only depends on the initial and final states of the system 

Ex. energy, enthalpy, entropy, change in temp, etc.

Surroundings

Everything in the universe around the system; can affect the system 

System

Part of the universe on which we focus our attention

Thermochemistry

The study of heat changes in chemical reactions

Thermodynamics

The study of energy and its interconversions

Work (w) ***

Force acting over a distance