Knewton unit 7 thermochemistry test-
with Questions with 100% Correct
Answers
When thermal energy is transferred from the system to its surroundings, heat (q) is: -
Answer negative
If a hot metal were placed in a calorimeter filled with cooler water, ideally, what would
the net heat exchange be? - Answer Heat transfer occurs until the two substances have
the same temperature. This is known as thermal equilibrium. If this occurs in a
calorimeter, ideally all of this heat transfer occurs between the two substances such as
metal and water (M and W), with no heat gained or lost by either the calorimeter or
the calorimeter's surroundings. Under these ideal circumstances, the net heat change is
zero. This is the basis for the heat transfer calculations where:
qM+qW=0
This relationship can be rearranged to show that the heat gained by the water is
equal to the heat lost by the metal:
−qM=qW
Ideally, the net heat change in a calorimetry experiment will be: - Answer zero
If all of the heat released by the system is absorbed by the calorimeter, there should
be no net heat change, which is an assumption we use to do calculations
, A thermochemical equation is a balanced chemical equation that also lists the: -
Answer hange in enthalpy
A thermochemical equation is a balanced chemical equation that provides the change in
enthalpy for the reaction. The ΔH is generally listed to the right of the balanced chemical
equation in a thermochemical equation.
Particles in a hot object, when compared to a colder object, have: - Answer greater
kinetic energy
Thermal energy is the energy of random motion of the particles in a sample, which is a
form of kinetic energy. The hotter the temperature of an object, the greater the
thermal energy, or the greater the average kinetic energy of the particles.
Heat is abbreviated as: - Answer q
The symbol for heat is a lowercase q. A lowercase h represents height, and an
uppercase H represents enthalpy. An uppercase T represents temperature.
Which of the following objects has more kinetic energy than it does potential energy?
a compressed spring in a pinball machine just before the ball is launched
a rollercoaster motionless at the top of a track
a yo-yo before it is released
the pendulum of a grandfather clock at the lowest point of its arc of motion - Answer
the pendulum of a grandfather clock at the lowest point of its arc of motion
Kinetic energy is the energy of motion. Each of the objects above are motionless—with
stored potential energy—except for the clock. At the bottom of its arc it will have the
greatest kinetic energy, which is then converted to potential energy as it swings back
up to one side.
When a substance undergoes a chemical reaction in a closed system, which of
the following will NOT change? (select all that apply)
with Questions with 100% Correct
Answers
When thermal energy is transferred from the system to its surroundings, heat (q) is: -
Answer negative
If a hot metal were placed in a calorimeter filled with cooler water, ideally, what would
the net heat exchange be? - Answer Heat transfer occurs until the two substances have
the same temperature. This is known as thermal equilibrium. If this occurs in a
calorimeter, ideally all of this heat transfer occurs between the two substances such as
metal and water (M and W), with no heat gained or lost by either the calorimeter or
the calorimeter's surroundings. Under these ideal circumstances, the net heat change is
zero. This is the basis for the heat transfer calculations where:
qM+qW=0
This relationship can be rearranged to show that the heat gained by the water is
equal to the heat lost by the metal:
−qM=qW
Ideally, the net heat change in a calorimetry experiment will be: - Answer zero
If all of the heat released by the system is absorbed by the calorimeter, there should
be no net heat change, which is an assumption we use to do calculations
, A thermochemical equation is a balanced chemical equation that also lists the: -
Answer hange in enthalpy
A thermochemical equation is a balanced chemical equation that provides the change in
enthalpy for the reaction. The ΔH is generally listed to the right of the balanced chemical
equation in a thermochemical equation.
Particles in a hot object, when compared to a colder object, have: - Answer greater
kinetic energy
Thermal energy is the energy of random motion of the particles in a sample, which is a
form of kinetic energy. The hotter the temperature of an object, the greater the
thermal energy, or the greater the average kinetic energy of the particles.
Heat is abbreviated as: - Answer q
The symbol for heat is a lowercase q. A lowercase h represents height, and an
uppercase H represents enthalpy. An uppercase T represents temperature.
Which of the following objects has more kinetic energy than it does potential energy?
a compressed spring in a pinball machine just before the ball is launched
a rollercoaster motionless at the top of a track
a yo-yo before it is released
the pendulum of a grandfather clock at the lowest point of its arc of motion - Answer
the pendulum of a grandfather clock at the lowest point of its arc of motion
Kinetic energy is the energy of motion. Each of the objects above are motionless—with
stored potential energy—except for the clock. At the bottom of its arc it will have the
greatest kinetic energy, which is then converted to potential energy as it swings back
up to one side.
When a substance undergoes a chemical reaction in a closed system, which of
the following will NOT change? (select all that apply)
