Studied by 3 people
potential energy
energy possessed by an object because of it’s position, composition, or condition
kinetic energy
energy possessed by an object because of it’s motion
thermal energy
energy associated with the random motion of atoms and molecules
chemical energy
potential energy stored within chemical bonds in a substance
do fast moving molecules feel hot or cold
hot
do slow moving molecules feel hot or cold
cold
what is heat
the transfer of thermal energy between two bodies at different temperatures
what direction does heat flow
from hotter object to colder object
system
substance undergoing the chemical or physical change
in HCl + NaOH what is the system
H+, Cl-, Na+, OH-
in HCl + NaOH what are the surroundings?
the water surrounding the ions
what happens to the flow of heat in an endothermic process
from the surroundings to the system
is q positive or negative in an endothermic process
+
does endothermic absorb or release heat
absorbs
does an exothermic process absorb or release heat
release
what is the direction of heat flow in an exothermic process
from the system to the surroundings
is q negative or positive in an exothermic reaction
-
how many calories to J/kj
4.184J
how many kcal to j/kj
4.184 kj
what does 1 cal do to 1g of water
raises 1 degree celcius
what is heat capacity
amount of heat absorbed or released by a body of matter when it experiences a temeprature change of 1C
what variable is heat capacity
C
what units is heat capacity
J/degrees C
what is specific heat capacity
the amount of heat needed to raise the temperature of one gram of a substance by 1 degree celcius
what are the units of specific heat
J/g degrees c
Fe has a lower c than water. So, if they absorb the same amount of heat, which will have a greater temperature change?
Fe
What is a calorimeter for
measure the amount of heat and direction of flow in a process
what is the surroundings in a calorimetry equation
water
what happens when thermal equilibrium is reached
the system and surroundings will be at the same final temp
is q reaction equal to the negative or positive q calorimeter?
negative
if temperature of surroundings increases, is it exo or endothermic?
exothermic
if the temeprature of surroundings decreases, is it exo or endothermic?
endothermic
what do you have to assume in a coffee-cup calorimeter
all heat evolved from the reaction is absorbed by the water
what is the difference in calculating the dissolution of a solid in water in a coffee cup calorimeter problem
you use the total mass of the solution
when do you need to use a bomb calorimeter
releases a large amount of heat or uses gasses
is the delta t of the calorimeter equal to, greater than, or less than the delta t of water?
equal to
if the amount of water in the calorimeter is not specified, what do you do?
omit qwater from the equation
what equation does a bomb calorimeter use
-[(ccal x deltat) + (mcdeltatwater)]
what is enthalpy
the heat flow at constant pressure
what is the change in enthalpy ( delta H)
the change in heat flow at constant pressure (delta H = q)
is delta h porportional to the coefficients shown
yup
what is pressure in standard state
1 bar
what is the concentration of dissolved species in standard state
1 M
is it exothermic or endothermic if delta h is -
exothermic
is it exothermic or endothermic if delta h is +
endothermic
what are the ways to calculate delta h Rxn
calorimetry, hess’s law, delta h rxn = sum of delta h products - sum of delta h reactants
what is the movement from solid to liquid phase called
fusion
what is the movement from liquid to gaseous state called
vaporization
what is the movement from gas to liquid called
condensation
what is the movement from liquid to solid called
solidification
what is the movement from gas to solid called
deposition
what is the movement from solid to gas called
sublimation
are condensation, solidification, and deposition exo or endothermic
exothermic
are fusion, vaporization, and sublimation exo or endothermic
endothermic
how to solve how much heat is required to convert ice to water vapor at a certain temp
mcdeltat for heating ice, ndeltah for melting ice, mcdeltat for heating water, ndeltah for boiling water, mcdeltat for heating steam, add up all of the qs
if t surroundings increases is the reaction exo or endothermic
exothermic
if t surroundings decreases is the reaction exo or endothermic
endothermic
Note 
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