Chem 120 Exam 1 | Questions And
Answers | Latest Exam 2026-2027 |
GRADED A+
____= the capacity to do work or transfer heat -ANSWER energy
____= objects being studied -ANSWER system
___=everything outside of the system -ANSWER surroundings
_____= are dependent of the initial and final states of a system. They are represented
by uppercase variables: V, E, P, T -ANSWER state functions
_____= are dependent on the path that a system takes to get from the initial to final
state. They are represented by lower case variables: q, w, t -ANSWER path functions
When a flask is hot energy is moving from _____ to ____ molecules. The change in
energy is _____ than 0. -ANSWER system
surroundings
less
When a flask is cold energy is moving from _____ to ____ molecules. The change in
energy is ___ than 0. -ANSWER surrounding
system
greater
____ law of thermodynamics states that energy can be converted from one form to
another, but it cannot be created or destroyed -ANSWER first
____ is the transfer of thermal energy between two bodies that are at different
temperatures -ANSWER heat (q)
_____ is the motion over some distance against an opposing force or the change in
volume against a pressure -ANSWER work (w)
_____ is when heat is released in a system -ANSWER exothermic
_____ is when heat is absorbed by the system -ANSWER endothermic
____= heat is released by the system (exothermic) -ANSWER -q (negative heat)
___- heat absorbed by the system (endothermic) -ANSWER +q (positive heat)
,_____= work done on the system by the surroundings -ANSWER +w (positive work)
___= work don on the surroundings by the system -ANSWER -w (negative work)
What is the overall change in internal energy for a system that releases 43J in heat in a
process in which no work is done? -ANSWER -43J
-43J + 0= -43J
A reaction occurs in which ^U=-143kJ. If 123kJ of heat was absorbed by the system,
then was work done by the system or on the system? -ANSWER work was done by the
system
-143=123 + w
w=-
Which is a highest energy state of water?
A. H2O (s)
B. H2O (l)
C. H2O (g) -ANSWER C. H2O (g)
Is energy absorbed or released when water evaporates? -ANSWER absorbed
______= amount of heat required to raise the temperature of one gram of a substance
by one degree Celsius -ANSWER specific heat (c)
Equal mass blocks of copper and aluminum are placed in a furnace at 300 degrees.
Which block will reach 300 degrees first?
specific heat of Al= 0.900 J/g degrees C
specific heat of Cu= 0.385 J/g degrees C -ANSWER copper
A 466g sample of water is heated from 8.50 C to 74.6 C. Calculate the amount of heat
absorbed by the water. -ANSWER 128.878kJ
look at Jan 22 notes
A metal radiator is made from 26.0x10^3g of iron. The specific heat of iron is 0.449J/g
C. How much heat must be supplied to the radiator to raise its temperature from 25.0 to
55.0 C? -ANSWER 350kJ
look at Jan 22 notes
A 15.5g piece of chromium, heated to 100.0 C is dropped into 55.5g of water at 16.5 C.
The final temperature of the metal and the water is 18.9 C. What is the specific heat of
chromium? -ANSWER 0.443 J/g C
, look at Jan 22 notes
A 30g sample of water at 28 C is mixed with 50g of water at 33 C. Calculate the final
temperature of the mixture assuming no heat is lost to the surroundings. Specific heat of
water = 4.184 J/g C. -ANSWER 31.1 C
look at Jan 22 notes
____= the measurement of heat changes -ANSWER calorimetry
A decomposition reaction occurs in a coffee cup calorimeter. The calorimeter initially
contains 50g of water of 22 C. The temp. of the water increases 50 C. Assume all heat
was transferred to only the water. What is the heat of this reaction? If 10g of the
reactant were used with a molar mass of 50 g/mol, then what is the heat of reaction per
mole of reactant? -ANSWER 1. -5.86kJ
2. -29.3 kJ/mol
look at Jan 22 notes
A coffee cup calorimeter contains 125g of water at 24.2 C. When 10.5g of KBr (FW
119.00 g/col), also at 24.2 C, is dissolved in the water the temperature decreases at
21.1 C. What is the energy change in kJ/mol when 1 mole of KBr dissolves. You may
assume that no heat is transferred to or from the surroundings or the calorimeter and
that the heat capacity of the solution of 4.184 J/G C -ANSWER 18.4 kJ/mol
look at Jan. 22 notes
_____ is defined as heat flow under constant pressure. It is a ____ function. -ANSWER
enthalpy
state
_______: deltaH>0, energy absorbed -ANSWER endothermic
____: deltaH<0, energy is evolved -ANSWER exothermic
Is freezing exothermic or endothermic? -ANSWER exothermic
How much energy does it take to warm 10g of ice from -5 C to liquid water at 15 C?
specific heat of Ice= 2.108 J/g C
specific heat of liquid= 4.184 J/g C -ANSWER 4.06 kJ
look at Jan 26th notes
____ law= if a reaction is carried out in a series of steps, deltaH for the overall reaction
will be equal to the sum of the enthalpy changes for the individual steps. -ANSWER
Hess's
Answers | Latest Exam 2026-2027 |
GRADED A+
____= the capacity to do work or transfer heat -ANSWER energy
____= objects being studied -ANSWER system
___=everything outside of the system -ANSWER surroundings
_____= are dependent of the initial and final states of a system. They are represented
by uppercase variables: V, E, P, T -ANSWER state functions
_____= are dependent on the path that a system takes to get from the initial to final
state. They are represented by lower case variables: q, w, t -ANSWER path functions
When a flask is hot energy is moving from _____ to ____ molecules. The change in
energy is _____ than 0. -ANSWER system
surroundings
less
When a flask is cold energy is moving from _____ to ____ molecules. The change in
energy is ___ than 0. -ANSWER surrounding
system
greater
____ law of thermodynamics states that energy can be converted from one form to
another, but it cannot be created or destroyed -ANSWER first
____ is the transfer of thermal energy between two bodies that are at different
temperatures -ANSWER heat (q)
_____ is the motion over some distance against an opposing force or the change in
volume against a pressure -ANSWER work (w)
_____ is when heat is released in a system -ANSWER exothermic
_____ is when heat is absorbed by the system -ANSWER endothermic
____= heat is released by the system (exothermic) -ANSWER -q (negative heat)
___- heat absorbed by the system (endothermic) -ANSWER +q (positive heat)
,_____= work done on the system by the surroundings -ANSWER +w (positive work)
___= work don on the surroundings by the system -ANSWER -w (negative work)
What is the overall change in internal energy for a system that releases 43J in heat in a
process in which no work is done? -ANSWER -43J
-43J + 0= -43J
A reaction occurs in which ^U=-143kJ. If 123kJ of heat was absorbed by the system,
then was work done by the system or on the system? -ANSWER work was done by the
system
-143=123 + w
w=-
Which is a highest energy state of water?
A. H2O (s)
B. H2O (l)
C. H2O (g) -ANSWER C. H2O (g)
Is energy absorbed or released when water evaporates? -ANSWER absorbed
______= amount of heat required to raise the temperature of one gram of a substance
by one degree Celsius -ANSWER specific heat (c)
Equal mass blocks of copper and aluminum are placed in a furnace at 300 degrees.
Which block will reach 300 degrees first?
specific heat of Al= 0.900 J/g degrees C
specific heat of Cu= 0.385 J/g degrees C -ANSWER copper
A 466g sample of water is heated from 8.50 C to 74.6 C. Calculate the amount of heat
absorbed by the water. -ANSWER 128.878kJ
look at Jan 22 notes
A metal radiator is made from 26.0x10^3g of iron. The specific heat of iron is 0.449J/g
C. How much heat must be supplied to the radiator to raise its temperature from 25.0 to
55.0 C? -ANSWER 350kJ
look at Jan 22 notes
A 15.5g piece of chromium, heated to 100.0 C is dropped into 55.5g of water at 16.5 C.
The final temperature of the metal and the water is 18.9 C. What is the specific heat of
chromium? -ANSWER 0.443 J/g C
, look at Jan 22 notes
A 30g sample of water at 28 C is mixed with 50g of water at 33 C. Calculate the final
temperature of the mixture assuming no heat is lost to the surroundings. Specific heat of
water = 4.184 J/g C. -ANSWER 31.1 C
look at Jan 22 notes
____= the measurement of heat changes -ANSWER calorimetry
A decomposition reaction occurs in a coffee cup calorimeter. The calorimeter initially
contains 50g of water of 22 C. The temp. of the water increases 50 C. Assume all heat
was transferred to only the water. What is the heat of this reaction? If 10g of the
reactant were used with a molar mass of 50 g/mol, then what is the heat of reaction per
mole of reactant? -ANSWER 1. -5.86kJ
2. -29.3 kJ/mol
look at Jan 22 notes
A coffee cup calorimeter contains 125g of water at 24.2 C. When 10.5g of KBr (FW
119.00 g/col), also at 24.2 C, is dissolved in the water the temperature decreases at
21.1 C. What is the energy change in kJ/mol when 1 mole of KBr dissolves. You may
assume that no heat is transferred to or from the surroundings or the calorimeter and
that the heat capacity of the solution of 4.184 J/G C -ANSWER 18.4 kJ/mol
look at Jan. 22 notes
_____ is defined as heat flow under constant pressure. It is a ____ function. -ANSWER
enthalpy
state
_______: deltaH>0, energy absorbed -ANSWER endothermic
____: deltaH<0, energy is evolved -ANSWER exothermic
Is freezing exothermic or endothermic? -ANSWER exothermic
How much energy does it take to warm 10g of ice from -5 C to liquid water at 15 C?
specific heat of Ice= 2.108 J/g C
specific heat of liquid= 4.184 J/g C -ANSWER 4.06 kJ
look at Jan 26th notes
____ law= if a reaction is carried out in a series of steps, deltaH for the overall reaction
will be equal to the sum of the enthalpy changes for the individual steps. -ANSWER
Hess's
