une chem 1011 final week 11 & 12 questions
with complete solutions
Which of the following is always true?
-Spontaneous changes cause an increase in the entropy of the
universe
-Heat will flow from a cooler object to a hotter object
-Processes that involve an increase in entropy of the system are
spontaneous
-The change in entropy of the universe is the same as the change
in entropy of the surroundings correct answer: Spontaneous
changes cause an increase in the entropy of the universe
A pure, perfectly crystalline solid at 0 K correct answer: has
zero entropy
In the Gibbs free energy relationshipΔG = ΔH - TΔSTΔS for a
spontaneous exothermic process represents correct answer: the
energy lost to the surroundings
ΔG is correct answer: The free energy change for a process
calculated for any set of conditions
A process with a ΔG > 0 will be correct answer:
nonspontaneous
An exothermic process that involves an increase in entropy
correct answer: will always be spontaneous
, The equilibrium reaction N2O4(g) ⇌ 2 NO2(g) has an
equilibrium constant K = 1.7 x 103 at 500 K. For this reaction
under these conditions correct answer: ΔG < 0, and more
products will be present
Use the following standard enthalpy and entropy data to
calculate the free energy change for the reaction of methane and
chlorine gas to produce chloromethane at 298 K: CH2Cl2 + Cl2
⟶ CHCl3 + HCl correct answer: -96.8 kJ
Using the following data:
Br2(g) ΔGf° = 3.14 kJ/molHBr(g) ΔGf° = -53.4 kJ/molCalculate
the free energy change for the reaction H2 + Br2 ⟶ 2 HBr
correct answer: -110. kJ
The reaction of hydrogen gas and oxygen gas to make water, 2
H2(g) + O2(g) ⟶ 2 H2O(g), has a standard free energy change
ΔG° = -457.2 kJ/mol. What is the free energy change under the
following conditions?PH2 = 0.150 atmPO2 = 0.200 atmPH2O =
1.10 atmT = 400 K correct answer: -439
Processes that involve an increase in entropy of the system (ΔS
> 0) correct answer: are often positive
The objects are at different temperatures, and heat flows from
the hotter to the cooler object. what type of reaction is this?
correct answer: spontaneous
with complete solutions
Which of the following is always true?
-Spontaneous changes cause an increase in the entropy of the
universe
-Heat will flow from a cooler object to a hotter object
-Processes that involve an increase in entropy of the system are
spontaneous
-The change in entropy of the universe is the same as the change
in entropy of the surroundings correct answer: Spontaneous
changes cause an increase in the entropy of the universe
A pure, perfectly crystalline solid at 0 K correct answer: has
zero entropy
In the Gibbs free energy relationshipΔG = ΔH - TΔSTΔS for a
spontaneous exothermic process represents correct answer: the
energy lost to the surroundings
ΔG is correct answer: The free energy change for a process
calculated for any set of conditions
A process with a ΔG > 0 will be correct answer:
nonspontaneous
An exothermic process that involves an increase in entropy
correct answer: will always be spontaneous
, The equilibrium reaction N2O4(g) ⇌ 2 NO2(g) has an
equilibrium constant K = 1.7 x 103 at 500 K. For this reaction
under these conditions correct answer: ΔG < 0, and more
products will be present
Use the following standard enthalpy and entropy data to
calculate the free energy change for the reaction of methane and
chlorine gas to produce chloromethane at 298 K: CH2Cl2 + Cl2
⟶ CHCl3 + HCl correct answer: -96.8 kJ
Using the following data:
Br2(g) ΔGf° = 3.14 kJ/molHBr(g) ΔGf° = -53.4 kJ/molCalculate
the free energy change for the reaction H2 + Br2 ⟶ 2 HBr
correct answer: -110. kJ
The reaction of hydrogen gas and oxygen gas to make water, 2
H2(g) + O2(g) ⟶ 2 H2O(g), has a standard free energy change
ΔG° = -457.2 kJ/mol. What is the free energy change under the
following conditions?PH2 = 0.150 atmPO2 = 0.200 atmPH2O =
1.10 atmT = 400 K correct answer: -439
Processes that involve an increase in entropy of the system (ΔS
> 0) correct answer: are often positive
The objects are at different temperatures, and heat flows from
the hotter to the cooler object. what type of reaction is this?
correct answer: spontaneous
