Download First Half of Thermo

ThermoChemistry
Group 3: Double X
First Half of ThermoChemistry
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Enthalpy is a state function of internal energy, constant
pressure and constant volume that helps us determine
the flow of energy in a reaction. If the change in
enthalpy is positive, the system gained heat from its
surroundings, so system endothermic. If the change in
enthalpy is negative, the system lost heat to its
surroundings, so the system is exothermic.
Kinetic energy is the energy involved with movement
and potential energy is the energy stored leading up to
a movement.
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Endothermic enters system exits solution and
exothermic exits system enters solution.
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First Law of Thermodynamics: The energy of the universe
is constant, in other words, energy is neither created nor
destroyed.
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In an endergonic reaction, energy is gained from
reaction whereas in an exergonic reaction, energy is
lost to the surrounding.
Questions:
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How is an isolated system
created? It seems that it would be
difficult to halt energy flow
between a system and its
surroundings.
With regards to open and closed
systems, would a system still be
considered closed if the only the
volume of the area increased, for
example in like a piston?
How do you determine energy
flow if the pressure or volume isn't
constant?
Second Half of
Thermo-Chemistry
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The change of H in the reaction is the
change in H products minus the change in
H reactants.
Hess's law states that if a reaction is carried
out in a series of steps, delta H for the
overall reaction reaction equals the sum of
the enthalpy changes for the individual
steps.
Because enthalpy is a state function, the
enthalpy change, delta H, associated with
any chemical reaction depends only on
the amount of matter that undergoes
change and on the the initial state of the
reactants and the final state of the
product.
Questions:
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How does multiplying the coefficient of
a reaction change the delta H of a
reaction?
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Why does the chemical reaction
depend on the amount of matter?
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Does the standard enthalpy change of
zero relates to thermodynamic energy,
in that first law of thermodynamic
stated energy cannot be destroyed nor
created? If so where does delta h
occur?
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Does enthalpy relate to Gibb's free
energy in any way?
Thermo-Chemistry
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If the change in enthalpy is positive, the system
gained heat from its surroundings, so system
endothermic. If the change in enthalpy is negative,
the system lost heat to its surroundings, so the system is
exothermic.
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Endothermic enters system exits solution and
exothermic exits system enters solution.

First Law of Thermodynamics: The energy of the
universe is constant, in other words, energy is neither
created nor destroyed.

Because enthalpy is a state function, the enthalpy
change, delta H, associated with any chemical
reaction depends only on the amount of matter that
undergoes change and on the the initial state of the
reactants and the final state of the product.

The change of H in the reaction is the change in H
products minus the change in H reactants.
Questions:

How is an isolated system
created? It seems that it would
be difficult to halt energy flow
between a system and its
surroundings.

How do you determine energy
flow if the pressure or volume
isn't constant?

Does enthalpy relate to Gibb's
free energy in anyway?