Thermochemistry Flashcards
What is the Law of Conservation of energy?
Energy cannot be created nor destroyed only transfered
What is Enthalpy
Enthalpy is the amount of heat released or absorbed during a physical or chemical process (the change in heat)
what is specific heat capacity
the quantity of heat required to raise the temp of a unit mass of a substance by one degree Celsius (j(g^. celsius)
What is Calorimetry
The measurement of how much heat is released or absorbed during a physical or chemical change
system vs surrounding
the area where a reaction takes place
vs
outside of the system
what are the three types of systems and what do they mean
Closed system: matter cannot enter or leave but energy can (lid over pot on the stove, the water stays in heat escapes)
Open system: matter and energy can enter or leave (open pot on stove heat can escape matter can enter)
Isolated system: does not allow heat or matter to leave (lid on pot and stove turned off)
State similarities/ diffrences
(movement, volume, shape)
Solid forms lattice
liquid moment takes shape of contanier
gas lots of movement spreads out
Endothermic vs exothermic
takes in heat surroundings get colder + change in temp
gives off heat surroundings get hotter
- change in temp
Beer lambert law
formulas to remember?
describes the relationship between the absorbance of light by a substance and its concentration in solution
a=ebc
(a=Absorbance)(b=constant)(c=concentration
line of best fit
y= ax+b
y=absobance
x=concemtration
a=some number
Phase change names/ endo vs exothermic
solid to liquid (melting) endothermic
liquid to solid (freezing) exothermic
solid to gas ( Sublimation)
endothermic
gas to solid (deposition) exothermic
gas to liquid (condensation) exothermic
liquid to gas (Evaporation) endothermic
what is temp
the measurement of heat and it is directly proportional to average kinetic energy of particles.
what is heat
the transfer of thermal energy from two systems at different temps
Calculate the amount of heat needed
to increase the temperature of
250.g of water from 20.0C to
56.0C. specific heat capacity of water liquid +4.18
q = m c ΔT
q = (250.g) (4.18 J/g oC) (56.0oC – 20.0oC)
q = 37 620 J = 37.6 kJ
How do you calculate heat? when ∆T = 0
what do the variables mean?
q =nΔH
q= heat
n= moles
ΔH= enthalapy
How do you calculate heat? when ∆T not = 0
what do the variables mean?
q=m c ∆T
q= heat
m= mass
∆T= change in temperature (Tfinal-Tinitial)
c= specific heat capacity (J/(g oC)
what is the Kelvin Temperature Scale
K = 0C + 273.15
0C = K – 273.15
Absolute Zero (0K) = -273.150C
pressure is inversely proportional to?
volume
volume and pressure is directly porportional to?
temperature
volume is directly porportional to
the amount of gas
change in
concentration
pressure
volume
temp
catalyst
is there a shift in equilibrium
will it change kc?
yes
yes
yes
yes
no
no
no
no
yes
no
delta G is less than 0
delta G is greater than 0
delta G is equal to 0
reactants is favoured thermodynamically is favoured
products is favoured thermodynamically unfavoured
the reaction is at equilibrium
If Kc ˃˃ 1.
If Kc ˂˂ 1.
The equilibrium position will lie to the right and favour the products.
The equilibrium position will lie to the left and favour the reactants.
Homogenous vs. heterogeneous equilibria.
same states
diffrent states
