Spontaneous Reactions and Maximum Concentration
Not what you're looking for?
Calculate the maximum concentration (in M) of sulfide ions in a solution containing 0.181 M of lead ions. The Ksp for lead sulfide is 3.4 x 10-28.
a. 1.9 x 10-27
b. 9.4 x 10-28
c. 1.5 x 10-26
d. 3.0 x 10-25
e. 3.4 x 10-28
A reaction that is spontaneous ___________.
a. will proceed as written without outside intervention
b. will be very rapid as written
c. will occur very slowly
d. is also spontaneous in the reverse direction
e. has an equilibrium position that lies very far to the left
In a spontaneous process, __________.
a. the path between reactants and products is irreversible
b. the reverse process is also spontaneous
c. forward and reverse processes occur at the same rate
d. the reverse process occurs at a higher rate than the forward process
e. the path between reactants and products is reversible
Which of the following is a reversible process?
a. Melting of ice at 0°C and 1 atm
b.Freezing of water at -10°C and 1 atm
c.Evaporation of water at 25°C and 1 atm
d.Freezing of water at -25°C and 1 atm
e.Melting of ice at 25°C and 1 atm
Given the following table of thermodynamic data, determine the normal boiling point (in °C) of TiCl4.
Substance ΔHf° S°
TiCl4(g) -763.2 kJ/mol 354.9 J/mol-K
TiCl4(l) -804.2 221.9
a. 308.3
b. 41.0
c. 35.3
d. 273.3
e. 133.0
Which equation represents a reaction that is decreasing in entropy as the reaction proceeds?
a. H2O(l) H2O(g)
b. 2C(s) + O2(g) 2CO(g)
c. CaCO3(s) CaO(s) + CO2(g)
d. 2H2(g) + O2(g) 2H2O(l)
e. 2Na(s) + 2H2O(l) 2NaOH(aq) + H2(g)
For which one of the following reactions should the sign of ΔS be negative?
a. C(s) + O2(g) CO2(g)
b. H2O(l) H2O(g)
c. NH3Cl(s) HCl(g) + NH3(g)
d.2NaCl(s) + H2SO3(aq) 2HCl(g) + Na2SO4(s)
e.2SO2(g) + O2(g) 2SO3(g)
Consider a pure, crystalline solid being heated from absolute zero to some very high temperature. Which one of the following processes produces the greatest increase in the entropy of the substance?
a. Heating the liquid
b. Boiling the liquid
c. Heating the solid
d. Heating the gas
e. Melting the solid
Given the following table of thermodynamic data, determine the ΔS° (in J/mol-K) for the reaction:
C2H2(g) + 2 H2(g) C2H6(g).
Substance S°
C2H2(g) 200.8 J/mol-K
C2H4(g) 219.4
C2H6(g) 229.5
H2(g) 130.58
a. -111.98
b. -101.88
c. -232.46
d. +101.88
e. +111.98
Which species below has/have ΔG°f = 0?
a.Both Co(s) and H2(g)
b. HCo(PF3)4(g)
c. Co(s)
d. H2(g)
e. PF3(g)
Purchase this Solution
Solution Summary
The solutions respond to many multiple choice questions relating to maximum concentration, spontaneous reactions, thermodynamic reactions, reversible processes, etc.
Solution Preview
Question: Calculate the maximum concentration (in M) of sulfide ions in a solution containing 0.181 M of lead ions. The Ksp for lead sulfide is 3.4 x 10-28.
a. 1.9 x 10-27
b. 9.4 x 10-28
c. 1.5 x 10-26
d. 3.0 x 10-25
e. 3.4 x 10-28
Response: Lead sulfide is PbS. Therefore, we know that
Ksp = [Pb+2][S-2] = 3.4x10-28 = (0.181)[S-2]
Now, all you do is solve for [S-2] and you've got your answer!
Question: A reaction that is spontaneous ___________.
a. will proceed as written without outside intervention
b. will be very rapid as written
c. will occur very slowly
d. is also spontaneous in the reverse direction
e. has an equilibrium position that lies very far to the left
Response: Spontaneity has nothing to do with kinetics since spontaneity is a thermodynamic property; therefore, it has nothing to do with speed of the reaction. Likewise, if the reaction is spontaneous it will proceed in the forward direction as written, and not in the reverse direction. Spontaneous means that the reaction will just happen, without any reference to a time frame. The conversion of graphite to diamond is spontaneous, but it sure does take a lot of time!
Question: In a spontaneous process, __________.
a. the path between reactants and products is irreversible
b. the reverse process is also spontaneous
c. forward and reverse processes occur at the same rate
d. the reverse process occurs at a higher rate than the forward process
e. the path between reactants and products is reversible
Response: If a process is spontaneous, its reverse is never spontaneous. And remember, once again, when we start talking about rate, we're no longer speaking of spontaneity; therefore, none of the responses that mention rate are correct either. Therefore, we've got two options left, (a) and (e). From the question above, we should be able to rule out (e) since the reaction is actually ...
Purchase this Solution
Free BrainMass Quizzes
Thermochemistry
The quiz helps in revising basic concepts about thermochemistry.
Organic Chemistry Naming: Alkanes
This is a quiz which is designed to assist students with learning the nomenclature used to identify organic compounds. This quiz focuses on the organic compounds called Alkanes.
Functional groups in Organic Chemistry
You will be tested on the names of functional groups in Organic Chemistry. It is very important to know the functional groups to understand Organic reactions.
General Chemistry - Classification of Matter
This test will assess your knowledge on the classification of matter which includes elements, compounds and mixtures.