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Chap 6

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o1234567889q's version from 2017-11-15 19:51

Chap 6

Question Answer
Thermodynamicsthe scientific study of the interconversion of heat and other kinds of energy
State functionsproperties that are determined by the state of the system, regardless of how that condition was achieved (energy, pressure, volume, temperature)
First law of thermodynamicsenergy can be converted from one form to another, but cannot be created nor destroyed
examples of state functionsenergy and enthalpy (DH)
what is the earth's primary source of energyradiant energy which comes from the sun
the energy associated with the random motion of atoms and moleculesthermal energy
the energy stored within the collection of neutrons and protons in the atomnuclear energy
which energy is stored within bondschemical energy
the energy available by virtue of an object’s positionpotential energy
the transfer of thermal energy between two bodies that are at different temperaturesheat
what is the measure of thermal energytemperature
Thermochemistrythe study of heat change in chemical reactions
Systemthe specific part of the universe that is of interest to the study
Surroundingthe rest of the universe outside the system
Exothermic processtransfers thermal energy from the system to the surroundings
which reactions are also exothermicmetal displacement reactions
what does a closed system allow and not allowallows the transfer of energy but not matter/mass with its surroundings
isolated system does not allowenergy transfer
what does an open system freely exchange with its surroundingsenergy and matter
ways energy can be exchanged through an open systemthrough heat and work
example of an isolated systemthermos (container used to keep things cold or hot)
energythe ability to do work
workwhen an object moves against a force
work equationW=FD
letter representation of heatq
is heat intensive or extensive propertyextensive
extensive propertyrelies on the amount of matter present
examples of extensive propertiesvolume, mass, length, weight, size, heat
what term means the average kinetic energy of an objecttemperature
what term means the transfer of energyheat
what is internal energy a sum ofthe system's heat and work
first law of thermodynamicsThe internal energy of an isolated system stays constant
second law of thermodynamicsThe entropy of an isolated system tends to increase
entropydisorder
"in isolated system a reaction of liquid will never produce a solid, it will produce a gas because gas has more entropy(disorder) than liquid " what is this an example of2nd law of thermodynamics
what type of system are the laws of thermodynamics aboutisolated system
thermodynamicsthe scientific study of the interconversion of heat and other kinds of energy
State functionsproperties that are determined by the state of the system, regardless of how that condition was achieved
what are not state functionswork and heat
examples of state functionsenergy, pressure, volume, temperature
what does state refer totemperature, pressure, and the amount and type of substance present
opposite of state functionpath function
why is density a state functionbecause a substance's density is not affected by how the substance is obtained
enthalpy equationH=U+PV
enthalpyEnthalpy ( H ) is the sum of the internal energy ( U ) and the product of pressure and volume ( PV )
enthalpy is a state function becauseit only depends on the initial and final conditions, and not on the path taken to establish these conditions
first law of DE systemfirst law of thermodynamics
DE system equationDE=q+w
DEthe change in internal energy of a system
q the heat exchange between the system and the surroundings
equation for when a gas expands against a constant external pressurew=-PDV
work formulaw=f*d
what is DV in w=-PDVDV is final volume - initial volume
L atm to joulesx 101.325
thermodynamic equation at constant pressureDH=DE+PDV=qp
what is qv and qpheat at constant volume and heat at constant pressure
Henthalpy
heat given off or absorbed during a reaction at constant pressure is calledDH
what happens to the DH If you multiply both sides of the equation by a factor nthe DH must also change by the same factor of n
what happens to Dh if you reverse a reactionthe sign of the DH changes
what are the thermodynamic equation rules3 of em google
what must be specified in thermochemical equationsthe physical states of all reactants and products
conversion steps when solving "How much heat is evolved when 133 g of white phosphorus (P4) burn in air?"grams to moles to kj
DH and DE equationss of slide 35
Dnmoles of product gases - moles of reactant gases
Calorimetrythe measurement of heat changes in physical and chemical processes
specific heat (s) of a substance isthe amount of heat (q) required to raise the temperature of one gram of the substance by one degree Celsius
The heat capacity (C) of a substance isthe amount of heat (q) required to raise the temperature of a given quantity (m) of the substance by one degree Celsius
heat capacity and specific heat equationC=mxs
units for specific heat (s) J/g * degrees celcius
units for heat capacity (C)J/degrees celcius
heat equationsq=m*s*DT and q=C*DT
review slide38
units for qJ
what happens to enthalpy at constant pressureenthalpy becomes equal to heat flow (H=qp)
qrxnacronym stands for heat reaction
erxnacronym stands for energy reaction
qcalacronym stands for heat in the calorimetry
heat reaction equationqrxn=-(qwater+qCal)
specific heat of water4.184J/g*C
what to do when diluting an acid add acid to water and not water to acid! Exothermic!
go over slide52
Standard enthalpy of formation (DH0f)the heat change that results when one mole of a compound is formed from its elements at a pressure of 1 atm
memorize