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)
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller KenAli. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.49. You're not tied to anything after your purchase.