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