Chap. 17 SmartBook
What is a spontaneous process?
-A process that occurs under specified conditions without a continuous input of energy
In order to assess the spontaneity of a chemical reaction or physical process both the change in ___ and ___ associated with the reaction or process must be known.
-Blank 1: enthalpy -Blank 2: entropy
The change in entropy for a given process can be calculated by subtracting the ___ entropy of the system from the ___ entropy of the system.
-Blank 1: initial, starting, or beginning -Blank 2: final or ending
Which of the following correctly describes the first law of thermodynamics?
-Energy can be converted from one form to another, but it cannot be created or destroyed.
Which changes in state will result in an increase in the entropy of a substance? Select all that apply.
-Solid to liquid -Liquid to vapor -Solid to vapor
In order to predict whether the reaction below will be spontaneous under a given set of conditions, the change in both ______ and ______ for the process under those conditions must be known. N2(g) + 3H2(g) → 2NH3(g)
-enthalpy; entropy
A(n) ___ process is one that will occur without a continuous input of energy under a given set of conditions.
-spontaneous
Which of the following options correctly show how to calculate the entropy change of a system? Select all that apply.
-ΔS = S_f - S_i -ΔS = k ln Wf/Wi
Which statement correctly describes the relationship between the entropy and spontaneity of a process?
A reaction/process will be spontaneous if ΔSsys > 0 and ΔSsurr > 0.
The ___ law of thermodynamics states that ___ can neither be created nor destroyed.
Blank 1: first OR 1st Blank 2: energy
Given the balanced chemical equation CH4(g) + 2O2(g) → CO2(g) + 2H2O(g), which of the following equations should be used to calculate the total entropy change for this reaction? (States of matter have been omitted for simplification.)
S[CO2] + 2(S[H2O]) - S[CH4] - 2(S[O2])
In order to calculate the entropy change of a reaction using tabulated values, which of the following are necessary? Select all that apply.
Standard entropies of all components of the reaction A balanced equation
Which of the following statements correctly explain the increase in entropy that occurs when a substance changes from a solid to liquid, or liquid to gas? Select all that apply.
The freedom of movement of the particles increases in the change solid → liquid → gas. The energy of the particles increases during these phase changes.
Select which phase change, melting or vaporization, will have a greater increase in entropy for a given substance. In addition, select the statement(s) that explain(s) why.
The mobility of the particles increases much more when this phase change occurs. Vaporization of a substance
Which of the following options correctly describe standard entropy? Select all that apply.
The standard entropy of a substance is its absolute entropy at 1 atm. The units of standard entropy are Jmol⋅KJmol⋅K.
The first law of thermodynamics states that _____ is always conserved.
energy
The second law of thermodynamics states that the total _____ of the universe will _____ for any spontaneous process.
entropy; increase
A spontaneous process ______.
occurs under a given set of conditions
The___law of thermodynamics states that a spontaneous process will result in an increase in the entropy of the universe.
second or 2nd
The ___ entropy of a substance is its absolute entropy at 1 atm.
standard
A given process will be spontaneous if the entropy change of the ______ for the process is greater than zero. Select all that apply
universe
