# thermochemistry Flashcard

 thermodynamics
 study of energy transfer and energy transformationenergy absorbed/released
 energy
 ability to do work or to supply heat
 work
 when an object is moved by force over a distance
 heat
 difference in temperature when applied to energy
 what are the two ways energy is transferred
 heat and workobjects DON’T CONTAIN HEAT OR WORK!!its internal energy that does
 SI unit for energy
 joules ??
 kinetic energy
 1/2 mv^2kg, m/s
 potential energy
 everything needs to be stable so it goes to kinetic energy
 chemical potential energy
 interaction between particles in an atomconstant randomn motion so they have a kinetic energy>thermal energyaverage KE is proportional to temp in gas
 system in thermodynamcis
 something is defined as system and everything else in surroundingssystem is usually reactants and productsenergy transferred between both
 internal energy (U)
 sum of potential and kinetic energy change U= U final- U inital which is q+wfirst law of thermodynamics>no energy lost
 when heat or work goes into system
 positive
 when heat or work goes out of system
 negative
 in endothermic reactions
 systems absorbs heat so it is positive; energy converted to chemical potential energy
 in exothermic reactions
 system releases heat so it is negative; energy converted to thermal
 internal energy is what kind of system
 state function; unique value once the conditions of system have been defined
 geat and work are what kinds of system
 no state functions bc they depend on the system
 heat of reaction (q rxn)
 heat transfer at constant temperature
 heat reaction (q rxn) with constant volume
 qv would just equal Q +Wno work is actually done so all energy is heat
 heat reaction (q rxn) with constant pressure
 Q= change U +pchange V
 work equation
 w= -p change V
 enthaply (H)
 U +PV; heat transfer at constant pressure
 relationship with enthalpy and internal energy
 changes in both equals each other
 calorimeter definition
 measurement of quantity of heat
 heat capacity (C) and equation
 heat required to change the temperature of a system by 1 degree c;c=q/change in T
 molar heat capacity
 heat required to change the tempeature of system by 1 degree over 1 mole
 specific heat capacity
 heat capacity of 1 gram of sample
 heat equation with specific heat
 q= m (specific heat) (change in T)MCAT
 Coffee cup calorimeter
 same as change H which is q+w; constant pressure
 bomb calorimeter
 constant volume; can be change in U + p change in V; but normally justq+W
 hess’s law
 enthaply is state function so no matter the order or steps the energy with still be the same
 standard condition
 reference for thermo.1 atm, 1 M, 25 degree C,
 standard enthaply change
 enthaply change when all reactants and products are in their standard states