1
CHEMICAL THERMODYNAMICS TEST
WITH VERIFIED QUESTIONS AND
ANSWERS | GUARANTEED PASS |
LATEST 2025-2026
19.1 : Spontaneous Processes - Correct Answer-The first law
of thermodynamics states that energy is conserved (energy
is neither created nor destroyed, total energy remains
constant). Delta E = q + w (where E=change in
internal energy of system, q=heat absorbed, w=work
done on the system)
A process that occurs of its own accord without any ongoing
outside intervention is said to be spontaneous. A spontaneous
process is one that proceeds on its own accord without any
outside assistance- occurs in a definite direction. Processes that
are spontaneous in one direction are nonspontaneous in the
opposite direction.
Experimental conditions, such as temperature and pressure, are
often important in determining whether a process is spontaneous.
A chemical reaction is spontaneous if it occurs on its own accord,
regardless of its speed- not always an observable rate.
Thermodynamics can tell us the direction and extent of a
reaction but tells us nothing about the speed of a reaction.
1
, 2
Seeking a Criterion for Spontaneity - Correct Answer-The loss of
energy is a common feature of spontaneous change in mechanical
systems.
Bertholet suggested that the direction of spontaneous changes in
chemical systems was also determined by the loss of energy.
Although the majority of spontaneous reactions are exothermic,
there are spontaneous endothermic ones as well.
Quantities such as temperature, internal energy, and enthalpy
are state functions, properties that define a state and do not
depend on how we reach that state (heat and work are not
included).
One of the keys to understanding spontaneity is distinguishing
between reversible and irreversible paths between states.
Reversible and Irreversible Processes - Correct Answer-In a
reversible process, a system is changed in such a way that the
system and surroundings can be restored to their original state
by exactly reversing the change- completely restore the system
to its original condition with no net change to either the system
or its surroundings. An irreversible process is one that cannot
simply be reversed to restore the system and its surroundings to
their original states. A reversible change produces the mas.
amount of work that can be achieved by the system on the
surroundings (w_rev = w_max). When two objects at different
temperatures are in contact, heat will flow spontaneously from
the hotter object to the colder one.
2
CHEMICAL THERMODYNAMICS TEST
WITH VERIFIED QUESTIONS AND
ANSWERS | GUARANTEED PASS |
LATEST 2025-2026
19.1 : Spontaneous Processes - Correct Answer-The first law
of thermodynamics states that energy is conserved (energy
is neither created nor destroyed, total energy remains
constant). Delta E = q + w (where E=change in
internal energy of system, q=heat absorbed, w=work
done on the system)
A process that occurs of its own accord without any ongoing
outside intervention is said to be spontaneous. A spontaneous
process is one that proceeds on its own accord without any
outside assistance- occurs in a definite direction. Processes that
are spontaneous in one direction are nonspontaneous in the
opposite direction.
Experimental conditions, such as temperature and pressure, are
often important in determining whether a process is spontaneous.
A chemical reaction is spontaneous if it occurs on its own accord,
regardless of its speed- not always an observable rate.
Thermodynamics can tell us the direction and extent of a
reaction but tells us nothing about the speed of a reaction.
1
, 2
Seeking a Criterion for Spontaneity - Correct Answer-The loss of
energy is a common feature of spontaneous change in mechanical
systems.
Bertholet suggested that the direction of spontaneous changes in
chemical systems was also determined by the loss of energy.
Although the majority of spontaneous reactions are exothermic,
there are spontaneous endothermic ones as well.
Quantities such as temperature, internal energy, and enthalpy
are state functions, properties that define a state and do not
depend on how we reach that state (heat and work are not
included).
One of the keys to understanding spontaneity is distinguishing
between reversible and irreversible paths between states.
Reversible and Irreversible Processes - Correct Answer-In a
reversible process, a system is changed in such a way that the
system and surroundings can be restored to their original state
by exactly reversing the change- completely restore the system
to its original condition with no net change to either the system
or its surroundings. An irreversible process is one that cannot
simply be reversed to restore the system and its surroundings to
their original states. A reversible change produces the mas.
amount of work that can be achieved by the system on the
surroundings (w_rev = w_max). When two objects at different
temperatures are in contact, heat will flow spontaneously from
the hotter object to the colder one.
2
