07:44The Second Law of Thermodynamics: Heat Flow, Entropy, and MicrostatesProfessor Dave Explains486views
Multiple ChoiceAn ideal gas is allowed to expand at constant temperature. What are the signs of ∆H, ∆S & ∆G.1346views2rank7commentsHas a video solution.
Multiple ChoiceConsider the freezing of liquid water at 30°C. For this process what are the signs for ∆H, ∆S, and ∆G?1740views1rank4commentsHas a video solution.
Multiple ChoicePredict the sign of ∆S in the system for each of the following processes:a) Ag+ (aq) + Br - (aq) → AgBr (s)b) CI2 (g) → 2 CI - (g)c) CaCO3 (s) → CaO (s) + CO2 (g)d) Pb (s) at 50°C → Pb (s) at 70°C2049views4rank3commentsHas a video solution.
Multiple ChoiceFor each of the following reactions state the signs of ∆H (enthalpy) and ∆S (entropy):a) Fusion of ice.b) Sublimation of CO2c) Vaporization of aqueous water.d) Deposition of chlorine gas.e) Condensation of water vapor. 1730views2rank3commentsHas a video solution.
Multiple ChoiceDiethyl ether (C4H10O2, MW = 90.1 g/mol) has a boiling point of 35.6oC and heat of vaporization of 26.7 kJ/mol. What is the change in entropy (in kJ/K) when 3.2 g of diethyl ether at 35.6oC vaporizes at its boiling point?1319views1rank8commentsHas a video solution.
Multiple ChoiceUsing standard enthalpy and entropy values, calculate ΔG for the production of NH4NO3 at 20.0℃. 2 NH3 (g) + 2 O2 (g) → NH4NO3 (s) + H2O (l)246views
Multiple ChoiceIn order to calculate ΔH° for a reaction which of the following sets represents numerical values that would be required?183views
Multiple ChoiceCalculate the equilibrium constant for the formation of NO2 (g) from NO (g) and O2 (g) at 405 K. 2 NO (g) + O2 (g) → 2 NO2 (g)258views
Multiple ChoiceWhich reaction is most likely to have a positive ∆S of reaction?a) SiO2 (s) + 3 C (s) → SiC (s) + 2 CO (g)b) 6 CO2 (g) + 6 H2O (g) → C6H12O6 (s) + 6 O2 (g)c) CO (g) + Cl2 (g) → COCl2 (g)d) 3 NO2 (g) + H2O (l) → 2 HNO3 (l) + NO (g)232views2rank1commentsHas a video solution.
Multiple ChoiceIdentify sign of entropy changes for the following processes.1) freezing water to form ice2) ideal gas allowed to expand in a closed container at constant T3) mixing of two gases into one container4) NH2 (g) (1atm) → NH2 (g) (3 atm)5) gas mixture transferred from larger to smaller container239views2rankHas a video solution.
Multiple ChoiceSelect correct statement(s) below:a) gaseous CO2 has higher entropy in 2 L container compared to in 5 L containerb) N2O (g) contains higher standard molar entropy then HI (g)c) NaHCO3 (aq) + HC2H3O2 (aq) → NaC2H3O2 (aq) + H2O (l) + CO2 (g) has a negative ∆Sd) evaporation of water at 100 °C involves greater ∆S than evaporation at 112 °C225views2rank1commentsHas a video solution.
Textbook QuestionTwo different gases occupy the two bulbs shown here. Consider the process that occurs when the stopcock is opened, assuming the gases behave ideally. (d) How does the process affect the entropy of the surroundings? 561viewsHas a video solution.
Textbook QuestionWhich of the following reactions has ∆Ssys> 0? (a) N2(g) + 3H2(g) -> 2NH3(g) (b) Ag+(aq) + Cl-(aq) -> AgCl(s) (c) 2H2O2(aq) -> 2H2O(l) + O2(g) (d) 2I(g) -> I2(g)582viewsHas a video solution.
Textbook QuestionIf energy can flow in and out of the system to maintain a constant temperature during the process, what can you say about the entropy change of the surroundings as a result of this process? 327viewsHas a video solution.
Textbook QuestionPredict the signs of ΔH and ΔS for this reaction. Explain your choice. 541viewsHas a video solution.
Textbook QuestionIsomers are molecules that have the same chemical formula but different arrangements of atoms, as shown here for two isomers of pentane, C5H12. (b) Which isomer do you expect to have the higher standard molar entropy? Explain.721viewsHas a video solution.
Textbook QuestionIndicate whether each statement is true or false. (a) ΔS is a state function. (b) If a system undergoes a reversible change, the entropy of the universe increases. (c) If a system undergoes a reversible process, the change in entropy of the system is exactly matched by an equal and opposite change in the entropy of the surroundings. (d) If a system undergoes a reversible process, the entropy change of the system must be zero.853viewsHas a video solution.
Textbook QuestionThe normal boiling point of Br21l2 is 58.8 °C, and its molar enthalpy of vaporization is ΔHvap = 29.6 kJ>mol. (a) When Br21l2 boils at its normal boiling point, does its entropy increase or decrease?869viewsHas a video solution.
Textbook QuestionThe element gallium (Ga) freezes at 29.8 °C, and its molar enthalpy of fusion is ΔHfus = 5.59 kJ>mol. (a) When molten gallium solidifies to Ga(s) at its normal melting point, is ΔS positive or negative?1238viewsHas a video solution.
Textbook QuestionIndicate whether each statement is true or false. (c) In a certain spontaneous process the system undergoes an entropy change of 4.2 J>K; therefore, the entropy change of the surroundings must be -4.2 J>K.212viewsHas a video solution.
Textbook QuestionConsider the gas-phase reaction of AB3 and A2 molecules: (a) Write a balanced equation for the reaction. (b) What is the sign of the entropy change for the reaction?722viewsHas a video solution.
Textbook Question(a) Does the entropy of the surroundings increase for spontaneous processes?492viewsHas a video solution.
Textbook Question(b) In a particular spontaneous process the entropy of the system decreases. What can you conclude about the sign and magnitude of ΔSsurr?328viewsHas a video solution.
Textbook QuestionIdeal gases A (red spheres) and B (blue spheres) occupy two separate bulbs. The contents of both bulbs constitute the initial state of an isolated system. Consider the process that occurs when the stopcock is opened. (c) How dpes this process illustrate the second law of thermodynamics?286viewsHas a video solution.
Textbook QuestionRank the situations represented by the following drawings according to increasing entropy.269viewsHas a video solution.
Textbook QuestionTwo systems, each composed of two particles represented by circles, have 20 J of total energy. Which system, A or B, has the greater entropy? Why?366viewsHas a video solution.
Textbook QuestionTwo systems, each composed of three particles represented by circles, have 30 J of total energy. How many energetically equivalent ways can you distribute the particles in each system? Which system has greater entropy? 1366viewsHas a video solution.
Textbook Question(a) In a chemical reaction, two gases combine to form a solid. What do you expect for the sign of ΔS?1209viewsHas a video solution.
Textbook QuestionWithout doing any calculations, determine the sign of ΔSsys for each chemical reaction. b. CH2 ' CH2( g) + H2( g) ¡ CH3CH3( g)415views1rankHas a video solution.
Textbook QuestionWithout doing any calculations, determine the sign of ΔSsys for each chemical reaction. a. 2 KClO3(s) ¡ 2 KCl(s) + 3 O2( g)3295viewsHas a video solution.
Textbook QuestionWithout doing any calculations, determine the signs of ΔSsys and ΔS surr for each chemical reaction. In addition, predict under what temperatures (all temperatures, low temperatures, or high temperatures), if any, the reaction is spontaneous. a. C3H8( g) + 5 O2( g) ¡ 3 CO2( g) + 4 H2O( g) ΔH° rxn = -2044 kJ2575views1commentsHas a video solution.
Textbook QuestionFor each of the following pairs, predict which substance possesses the larger entropy per mole: (a) 1 mol of O21g2 at 300 °C, 0.01 atm, or 1 mol of O31g2 at 300 °C, 0.01 atm888viewsHas a video solution.
Textbook QuestionPredict the sign of the entropy change of the system for each of the following reactions: (d) Al2O31s2 + 3 H21g2¡2 Al1s2 + 3 H2O1g21402viewsHas a video solution.
Textbook QuestionPredict the sign of the entropy change of the system for each of the following reactions: (c) 3 C2H21g2¡C6H61g2856viewsHas a video solution.
Textbook QuestionPredict the sign of the entropy change of the system for each of the following reactions: (b) CaCO31s2¡CaO1s2 + CO21g2450viewsHas a video solution.
Textbook QuestionPredict the sign of the entropy change of the system for each of the following reactions: (a) N21g2 + 3 H21g2¡2 NH31g2595viewsHas a video solution.
Textbook QuestionDefine entropy, and give an example of a process in which the entropy of a system increases.486viewsHas a video solution.
Textbook QuestionPredict the sign of ΔSsys for each of the following processes: (d) Calcium phosphate precipitates upon mixing Ca1NO3221aq2 and 1NH423PO41aq2.512viewsHas a video solution.
Textbook QuestionPredict the sign of ΔSsys for each of the following processes: (c) Gaseous CO reacts with gaseous H2 to form liquid methanol, CH3OH.558viewsHas a video solution.
Textbook QuestionPredict the sign of ΔSsys for each of the following processes: (a) Molten gold solidifies.1238views1rankHas a video solution.
Textbook QuestionPredict the sign of ΔSsys for each of the following processes: (b) Gaseous Cl2 dissociates in the stratosphere to form gaseous Cl atoms.571viewsHas a video solution.
Textbook QuestionPredict the sign of the entropy change in the system for each of the following processes. (a) A solid sublimes. (b) A liquid freezes. (c) AgI precipitates from a solution containing Ag+ and I- ions. (d) Gaseous CO2 bubbles out of a carbonated beverage.525viewsHas a video solution.
Textbook QuestionCyclopropane and propylene are isomers that both have the formula C3H6. Based on the molecular structures shown, which of these isomers would you expect to have the higher standard molar entropy at 25 °C? 1909viewsHas a video solution.
Textbook QuestionThe standard entropies at 298 K for certain group 4A elements are: C(s, diamond) = 2.43 J>mol@K, Si1s2 = 18.81 J>mol@K, Ge1s2 = 31.09 J>mol@K, and Sn1s2 = 51.818 J>mol@K. All but Sn have the same (diamond) structure. How do you account for the trend in the S° values?918views1rankHas a video solution.
Textbook QuestionHow does the molar entropy of a substance change with increasing temperature?822viewsHas a video solution.
Textbook QuestionThree of the forms of elemental carbon are graphite, diamond, and buckminsterfullerene. The entropies at 298 K for graphite and diamond are listed in Appendix C. (b) What would you expect for the S° value of buckminsterfullerene (Figure 12.49, p. 509) relative to the values for graphite and diamond? Explain.901viewsHas a video solution.
Textbook QuestionFor each pair of substances, choose the one that you expect to have the higher standard molar entropy (S°) at 25 °C. Explain your choices. e. NO2( g); CH3CH2CH3( g)1565viewsHas a video solution.
Textbook QuestionRank each set of substances in order of increasing standard molar entropy (S°). Explain your reasoning. b. H2O(s); H2O(l ); H2O( g)503viewsHas a video solution.
Textbook QuestionRank each set of substances in order of increasing standard molar entropy (S°). Explain your reasoning. a. NH3( g); Ne( g); SO2( g); CH3CH2OH( g); He( g)2170views2rankHas a video solution.
Textbook QuestionWhich state has higher entropy? Explain in terms of probability. (a) A perfectly ordered crystal of solid nitrous oxide or a disordered crystal in which the molecules are oriented randomly (b) Quartz glass (an amorphous solid) or a quartz crystal517viewsHas a video solution.
Textbook QuestionRank each set of substances in order of increasing standard molar entropy (S°). Explain your reasoning. c. C(s, graphite); C(s, diamond); C(s, amorphous)671viewsHas a video solution.
Textbook QuestionFor a certain chemical reaction, ΔH° = -35.4 kJ and ΔS° = -85.5 J>K. (b) Does the reaction lead to an increase or decrease in the randomness or disorder of the system?601viewsHas a video solution.
Textbook QuestionWhich state in each of the following pairs has the higher entropy per mole of substance? (d) CO2 at STP or CO2 at 100 °C and 0.1 atm548views1rankHas a video solution.
Textbook QuestionWhich state in each of the following pairs has the higher entropy per mole of substance? (a) H2 at 25 °C in a volume of 10 L or H2 at 25 °C in a volume of 50 L395viewsHas a video solution.
Textbook QuestionWhich state in each of the following pairs has the higher entropy per mole of substance? (d) Water vapor at 150 °C and 1 atm or water vapor at 100 °C and 2 atm346viewsHas a video solution.
Textbook QuestionWhich state in each of the following pairs has the higher entropy per mole of substance? (b) N2 at STP or N2 at 0 °C and 10 atm342views1rankHas a video solution.
Textbook QuestionWhich state in each of the following pairs has the higher entropy per mole of substance? (a) Ice at -40 °C or ice at 0 °C287viewsHas a video solution.
Textbook QuestionMake a rough, qualitative plot of the standard molar entropy versus temperature for methane from 0 K to 298 K. Incorporate the following data into your plot: mp = -182 °C; bp = -164 °C; °S = 186.2 J/(K*mol) at 25 °C.404viewsHas a video solution.
Textbook QuestionAn isolated system is one that exchanges neither matter nor energy with the surroundings. What is the entropy criterion for spontaneous change in an isolated system? Give an example of a spontaneous process in an isolated system.224viewsHas a video solution.
Textbook QuestionGive an equation that relates the entropy change in the surroundings to the enthalpy change in the system. What is the sign of ∆Ssurr for the following? (a) An exothermic reaction (b) An endothermic reaction854viewsHas a video solution.
Textbook QuestionDetermine the sign of ΔSsys for each process. b. water freezing573viewsHas a video solution.
Textbook QuestionDetermine the sign of ΔSsys for each process. a. water boiling1117viewsHas a video solution.
Textbook QuestionConsider a twofold expansion of 1 mol of an ideal gas at 25 °C in the isolated system shown in Figure 18.1. (b) How does this process illustrate the second law of thermo-dynamics?282viewsHas a video solution.
Textbook QuestionFor each of the following processes, indicate whether the signs of ΔS and ΔH are expected to be positive, negative, or about zero. (e) A piece of charcoal is combusted to form CO21g2 and H2O1g2.726viewsHas a video solution.
Textbook QuestionThe reaction 2 Mg1s2 + O21g2¡2 MgO1s2 is highly spontaneous. A classmate calculates the entropy change for this reaction and obtains a large negative value for ΔS °. Did your classmate make a mistake in the calculation? Explain.291viewsHas a video solution.
Textbook Question(a) For each of the following reactions, predict the sign of ΔH° and ΔS ° without doing any calculations. (i) 2 Mg1s2 + O21g2Δ2 MgO1s2 (ii) 2 KI1s2Δ2 K1g2 + I21g2 (iii) Na21g2Δ2 Na1g2 (iv) 2 V2O51s2Δ4 V1s2 + 5 O21g2767viewsHas a video solution.
Textbook Question(b) Based on your general chemical knowledge, predict which of these reactions will have K 7 1. (i) 2 Mg1s2 + O21g2Δ2 MgO1s2 (ii) 2 KI1s2Δ2 K1g2 + I21g2 (iii) Na21g2Δ2 Na1g2 (iv) 2 V2O51s2Δ4 V1s2 + 5 O21g2332viewsHas a video solution.
Textbook QuestionIndicate and explain the sign of ΔSuniv for each process. a. 2 H2( g) + O2( g) → 2 H2O (l ) at 298 K.504views2commentsHas a video solution.
Textbook QuestionIn chemical kinetics, the entropy of activation is the entropy change for the process in which the reactants reach the activated complex. Predict whether the entropy of activation for a bimolecular process is usually positive or negative.1388viewsHas a video solution.
Textbook QuestionWhen most elastomeric polymers (e.g., a rubber band) are stretched, the molecules become more ordered, as illustrated here: Suppose you stretch a rubber band. (a) Do you expect the entropy of the system to increase or decrease?493viewsHas a video solution.
Open QuestionWithout doing any calculations, determine the sign of δssys for each of the following chemical reactions.201viewsHas a video solution.
Open QuestionWhich of the following liquid substances has the highest vapor pressure at its normal boiling point?191viewsHas a video solution.
Open QuestionRank these systems in order of decreasing entropy. rank from highest to lowest entropy. to rank items as equivalent, overlap them.637views2rank1commentsHas a video solution.
Open QuestionWhich of the following is a measure of randomness in a system?200viewsHas a video solution.
Open QuestionWhat will the sign on ∆S be for the following reaction and why? 2 Mg(s) + O2(g) → 2 MgO(s)43viewsHas a video solution.
Open QuestionClassify the phase changes by the signs of the system's ΔH° and ΔS°.52viewsHas a video solution.
Open QuestionWhich of the following has the largest standard molar entropy, S° (298.15 K)?45viewsHas a video solution.