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Entropy (S) The second factor involved in determining whether or not a process is spontaneous is the change in randomness or entropy (AS). Entropy is represented by the symbol S. Again, experience can help us understand the relationship between entropy and spontaneous processes. If we look at the two drawings below, we can predict which picture represents the stack of marbles "before" and after they are bumped. We expect the stack of marbles (less random, lower entropy) to be the...
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un plase uansion from a liquid to a gas • an increase in the number of moles of a gas during a chemical reaction EXAMPLE 17.1 Predicting the Sign of Entropy Change Predict the sign of AS for each process: (a) H2O(g) → H2O(1) (b) Solid carbon dioxide sublimes. (c) 2 N2O(g) —> 2 N2(8) + O2(g) SOLUTION (a) Since a gas has a greater entropy than a liquid, the entropy decreases and AS is negative. (b) Since a solid...
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Question 22 (1 point) (c) (d) Which transition represents a decrease in entropy of the system? (b) → (c) O (d) - (c) (a) → (c) (c) → (b) Question 20 (1 point) Ethanol melts at -114 °C and boils at 78 °C at a constant pressure of 1 atm. What state of matter must a sample of ethanol be in at 100°C and 1 atm? solid and liquid in equilibrium gas liquid O solid liquid and gas in equilibrium...
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Question Completion Status: QUESTION 6 1 points Save Anower The heat energy lost by an exothermic reaction is characterized as a negative change of enthalpy of the reaction (Arr. Heat energy is measured in joules while the closely related change in enthalpy is measured in kilojoules/mole accounting for the amount of heat produced by each molecule. If 485) of heat (a) is produced by a gven reaction of 0.032 moles of a given reactant, what is the molar enthalpy change...
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Which of the following factors determines what state a substance
exists in (select all that apply)
a.
Size of molecules
b.
Attractive forces between molecules
c.
Temperature
d.
The potential energy of the molecule
e.
Pressure
f.
Location of the molecules (in a jar/lab vs. 'outside' in the
atmosphere or ocean)
The term for changing from a liquid to a solid is _______ and is
_________. Put endothermic or exothermic in the second
blank.
The term for changing from a...
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34. The phase changes B-C and D - E are not associated with temperature increases because the heat energy (q) is consumed to A) increase distances between molecules B) break intramolecular bonds C) rearrange atoms within molecules D) increase the density of the sample gas liquid and gas TOC solid and liquid liquid B solid Heat added (1) 35. Which of these is a weak base? A) NaOH B) HCI E) CH3CH2OH C) Naci D) NH 36. When discussing energy...
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Gas pressure is caused by: A) barometers B) temperature C) gas molecules condensing into a liquid D) gas molecules hitting other gas molecules E) gas molecules colliding with surfaces 7) 8) What is the molarity of a solution that results when 21.3 g of (NH4)3PO4 (MM- 149 g/mol) is dissolved C) 0.357 M E) 1.61 x 10- water and brought to a total volume of 250.0 mL? D) 85.2 M B) 2.28 M A) 0.572 M 9) What is the...
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(2). Consider benzene in the gas phase, C&H(g). Use the heat of formation, AH, values below to answer the questions. (20 points дня (кJ/mo) Substance H(g) C(g) 217.94 718.4 82.9 (8°HӘ (a) What is the standard enthalpy change for the reaction that represents breaking all the bonds in gaseous benzene, CHg)? (6 points) (b) What is the chemical equation for the reaction that corresponds to breaking just the carbon-carbon bonds in gaseous benzene, CeH6()? Indicate the phase of each species...
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2.A certain compound undergoes a solid + liquid phase transition at -25.5°C. The entropy change AS, associated with the phase transition at this temperature is 53.8 J mor' K". What is the amount of heat energy. 9, that is absorbed to give this value for AS? (8 points) 8. Use the data in the appendix to calculate the standard entropy change, ASo, for the combustion of 1 mole of methane, CHe() (note: all reactants and products are in the gaseous...
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The vaporization of 1 mole of liquid water (the system) at
100.9°C, 1.00 atm, is endothermic.
H2O(l)+40.7kj -------> H2O(g)
Assume that at exactly 100.0°C and 1.00 atm total pressure, 1.00
mole of liquid water and 1.00 mole of water vapor occupy 18.80 mL
and 30.62 L, respectively.
Part 1
Calculate the work done on or by the system when 1.25 mol of
liquid H2O vaporizes.
Part 2
Calculate the water's change in internal energy
Entropy (S) The second factor involved in determining whether or not a process is spontaneous is the change in randomness or entropy (AS). Entropy is represented by the symbol S. Again, experience can help us understand the relationship between entropy and spontaneous processes. If we look at the two drawings below, we can predict which picture represents the stack of marbles "before" and after they are bumped. We expect the stack of marbles (less random, lower entropy) to be the...
un plase uansion from a liquid to a gas • an increase in the number of moles of a gas during a chemical reaction EXAMPLE 17.1 Predicting the Sign of Entropy Change Predict the sign of AS for each process: (a) H2O(g) → H2O(1) (b) Solid carbon dioxide sublimes. (c) 2 N2O(g) —> 2 N2(8) + O2(g) SOLUTION (a) Since a gas has a greater entropy than a liquid, the entropy decreases and AS is negative. (b) Since a solid...
Question 22 (1 point) (c) (d) Which transition represents a decrease in entropy of the system? (b) → (c) O (d) - (c) (a) → (c) (c) → (b) Question 20 (1 point) Ethanol melts at -114 °C and boils at 78 °C at a constant pressure of 1 atm. What state of matter must a sample of ethanol be in at 100°C and 1 atm? solid and liquid in equilibrium gas liquid O solid liquid and gas in equilibrium...
Question Completion Status: QUESTION 6 1 points Save Anower The heat energy lost by an exothermic reaction is characterized as a negative change of enthalpy of the reaction (Arr. Heat energy is measured in joules while the closely related change in enthalpy is measured in kilojoules/mole accounting for the amount of heat produced by each molecule. If 485) of heat (a) is produced by a gven reaction of 0.032 moles of a given reactant, what is the molar enthalpy change...
34. The phase changes B-C and D - E are not associated with temperature increases because the heat energy (q) is consumed to A) increase distances between molecules B) break intramolecular bonds C) rearrange atoms within molecules D) increase the density of the sample gas liquid and gas TOC solid and liquid liquid B solid Heat added (1) 35. Which of these is a weak base? A) NaOH B) HCI E) CH3CH2OH C) Naci D) NH 36. When discussing energy...
Gas pressure is caused by: A) barometers B) temperature C) gas molecules condensing into a liquid D) gas molecules hitting other gas molecules E) gas molecules colliding with surfaces 7) 8) What is the molarity of a solution that results when 21.3 g of (NH4)3PO4 (MM- 149 g/mol) is dissolved C) 0.357 M E) 1.61 x 10- water and brought to a total volume of 250.0 mL? D) 85.2 M B) 2.28 M A) 0.572 M 9) What is the...
(2). Consider benzene in the gas phase, C&H(g). Use the heat of formation, AH, values below to answer the questions. (20 points дня (кJ/mo) Substance H(g) C(g) 217.94 718.4 82.9 (8°HӘ (a) What is the standard enthalpy change for the reaction that represents breaking all the bonds in gaseous benzene, CHg)? (6 points) (b) What is the chemical equation for the reaction that corresponds to breaking just the carbon-carbon bonds in gaseous benzene, CeH6()? Indicate the phase of each species...
2.A certain compound undergoes a solid + liquid phase transition at -25.5°C. The entropy change AS, associated with the phase transition at this temperature is 53.8 J mor' K". What is the amount of heat energy. 9, that is absorbed to give this value for AS? (8 points) 8. Use the data in the appendix to calculate the standard entropy change, ASo, for the combustion of 1 mole of methane, CHe() (note: all reactants and products are in the gaseous...