AP Chem Thermo Exam
A cube of ice is added to some hot water in a rigid, insulated container, which is then sealed. There is no heat exchange with the surroundings. What has happened to the total energy and the total entropy when the system reaches equilibrium? Energy: ---- Entropy: ----
Energy: Remains Constant Entropy: Increases
What term best describes the energy in a chemical or physical change that is available to do useful work?
Free Energy
H2O(l) ---> H2O(s) When water freezes at its normal freezing point, 273.16 K and 1 atmosphere, what are the S, H, and G in proportion to zero.
H<0, S<0, V>0
What term best describes the amount of energy required to remove the most loosely bound electron, the valence electron, of an isolated gaseous atom?
Ionization Energy
What term best describes the energy that an object possesses due to its motion?
Kinetic Energy
What term best describes the energy required to break apart an ionic solid and convert its component atoms into gaseous ions?
Lattice Energy
What values of delta H and delta S indicate a reaction that is only thermodynamically favorable at high temperatures?
delta H > 0, delta S > 0
What does the variable "k" stand for?
equilibrium constant
Key phrases in the problem such as "heat energy is released" mean that the sign of the product must be
negative even if the answer produces a positive solution
When excess HF reacts with .33 mole of NaOH, a total of 12 kJ of heat energy is released. What is the value of delta H in kJ per mole NaOH consumed?
-36.0
Which of the following is most likely true for a solid solute with a highly endothermic heat of solution when dissolved in water?
The solid is more soluble at higher temperatures.
When you strike a match head on the side of a matchbox how are you affecting the combustion reaction?
You are supplying some of the energy of activation for the combustion reaction.
When k>1, delta G is: E is:
delta G is favorable(-), E is (+)
When k<1, delta G is:
delta G is unfavorable(+), E is (-)
What must the values of delta H and delta S be for a reaction that is thermodynamically favorable at all temperatures?
delta H < 0, delta S > 0
What must the values of delta H and delta S be for a reaction that is NOT thermodynamically favorable at all temperatures?
delta H > 0, delta S < 0
If no delta H is given, assume it's value is:
zero
