CHEM 162 EXAM QUESTIONS AND
ANSWERS
exothermic reaction - Correct Answers -a chemical reaction that releases energy to its
surroundings
"Heat" is best described as - Correct Answers -the energy transferred as a result of a
temperature difference
endothermic reaction - Correct Answers -A reaction that ABSORBS energy in the form
of heat
Iodine Vapor depositing on a cool surface - Correct Answers -exothermic
water condensing on a cold glass - Correct Answers -exothermic
propane burning - Correct Answers -exothermic
dry ice subliming - Correct Answers -physical, endothermic reaction
water freezing - Correct Answers -exothermic reaction
What is the term used to describe energy released when chemical bonds form? -
Correct Answers -potential energy
which species has a standard enthalpy of formation of zero (delta H of f degrees)
- C (s, diamond)
- NaCl (s)
- H2 (g)
- Br (l)
- Al2 (s) - Correct Answers -H2 (g)
which of the following ways is not a way to calculate enthalpy of a reaction?
using enthalpies of formation
the temperature change of a reaction is the enthalpy of reaction
the using a calorimeter to determine q cal, relate that. to q run and then delta h rxn
apply hess law using a series of known enthalpy of reactions to achieve an overall
enthalpy of reaction
, using bond energies of the reactants and products - Correct Answers -- the temperature
change of a reaction is the enthalpy of reaction
which of the following processes is spontaneous?
- you get an a in this course
- the Tupperware drawer is organized
- a broken touchscreen fixes itself
- rust turns into iron metal and oxygen gas
- sugar dissolves in tea - Correct Answers -- sugar dissolves in tea
an endothermic reaction - Correct Answers -transfer of energy from surroundings to
system
what is unique about a state function
- the value of a state function depends on how change occurs
- the value of a state function depends only on final and initial values
- state function is another term for the internal energy of a system
- the value of a state function depends on the history of the system - Correct Answers -
the value of a state function depends only on final and initial values
state function - Correct Answers -A function that depends only on the initial and final
states of a system, not on the path in between.
work - Correct Answers --P delta V
the horizontal part of heating curve indicates:
- the mass of material is irrelivant
the energy being added is being used to overcome intermolecular forces
there is no net energy change during phase changes
the material can no longer fain energy
the temperature is rising - Correct Answers -there is no net energy change during phase
changes
solid to gas is called - Correct Answers -sublimation
liquid to gas is called - Correct Answers -evaporation
liquid to solid is called - Correct Answers -freezing
solid to liquid - Correct Answers -melting
given = masses of each, same T initial and same amount energy lost, which will end
with the lowest temperature?
highest or lowest Cp (specific heat) - Correct Answers -A copper pot (lowest specific
heat (Cp)
ANSWERS
exothermic reaction - Correct Answers -a chemical reaction that releases energy to its
surroundings
"Heat" is best described as - Correct Answers -the energy transferred as a result of a
temperature difference
endothermic reaction - Correct Answers -A reaction that ABSORBS energy in the form
of heat
Iodine Vapor depositing on a cool surface - Correct Answers -exothermic
water condensing on a cold glass - Correct Answers -exothermic
propane burning - Correct Answers -exothermic
dry ice subliming - Correct Answers -physical, endothermic reaction
water freezing - Correct Answers -exothermic reaction
What is the term used to describe energy released when chemical bonds form? -
Correct Answers -potential energy
which species has a standard enthalpy of formation of zero (delta H of f degrees)
- C (s, diamond)
- NaCl (s)
- H2 (g)
- Br (l)
- Al2 (s) - Correct Answers -H2 (g)
which of the following ways is not a way to calculate enthalpy of a reaction?
using enthalpies of formation
the temperature change of a reaction is the enthalpy of reaction
the using a calorimeter to determine q cal, relate that. to q run and then delta h rxn
apply hess law using a series of known enthalpy of reactions to achieve an overall
enthalpy of reaction
, using bond energies of the reactants and products - Correct Answers -- the temperature
change of a reaction is the enthalpy of reaction
which of the following processes is spontaneous?
- you get an a in this course
- the Tupperware drawer is organized
- a broken touchscreen fixes itself
- rust turns into iron metal and oxygen gas
- sugar dissolves in tea - Correct Answers -- sugar dissolves in tea
an endothermic reaction - Correct Answers -transfer of energy from surroundings to
system
what is unique about a state function
- the value of a state function depends on how change occurs
- the value of a state function depends only on final and initial values
- state function is another term for the internal energy of a system
- the value of a state function depends on the history of the system - Correct Answers -
the value of a state function depends only on final and initial values
state function - Correct Answers -A function that depends only on the initial and final
states of a system, not on the path in between.
work - Correct Answers --P delta V
the horizontal part of heating curve indicates:
- the mass of material is irrelivant
the energy being added is being used to overcome intermolecular forces
there is no net energy change during phase changes
the material can no longer fain energy
the temperature is rising - Correct Answers -there is no net energy change during phase
changes
solid to gas is called - Correct Answers -sublimation
liquid to gas is called - Correct Answers -evaporation
liquid to solid is called - Correct Answers -freezing
solid to liquid - Correct Answers -melting
given = masses of each, same T initial and same amount energy lost, which will end
with the lowest temperature?
highest or lowest Cp (specific heat) - Correct Answers -A copper pot (lowest specific
heat (Cp)
