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Spontaneous Reaction Solutions Library

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162 solutions

Spontaneous Reaction

Q. Which of the following is true regarding a non-spontaneous process: I. The process will occur with an outside influence II. The process will occu...

Solved • Apr 20, 2017

Spontaneous Reaction

Q. The following reaction is endothermic: 2 H2O (l) → 2 H2(g) + O2(g) Which of the following answers correctly describes the spontaneity: A. This r...

Solved • Apr 20, 2017

Spontaneous Reaction

Q. Given that the normal freezing point of ammonia is -78°C. Predict the signs of ΔH, ΔS and ΔG for ammonia when it freezes at -80°C and 1 atm.NH3(l) ...

Solved • Mar 6, 2017

Spontaneous Reaction

Q. Which of the following are the thermodynamic signs for the mixing of a gas with water?A. ΔH +, ΔS+B. ΔH +, ΔS-C. ΔH -, ΔS+D. ΔH -, ΔS-

Solved • Feb 20, 2017

Spontaneous Reaction

Q. Which of the following is a description of a phase change for which ΔG is positive. A. Liquid water forming steam at standard pressure and 94°CB. L...

Solved • Feb 20, 2017

Spontaneous Reaction

Q. At 25 oC, ΔHo = 1.895 kJ and ΔSo = – 3.363 J/K for the transition  C (graphite) →  C (diamond) Based on their data a) Graphite is more stable th...

Solved • Feb 17, 2017

Spontaneous Reaction

Q. For the reaction given below, ΔH° = -1516kJ and ΔS° = -432.8J/K at 25°C SiH4(g) + 2O2(g) →  SiO2(g) + 2H2O(l)  The reaction is spontaneous: a. on...

Solved • Jan 30, 2017

Spontaneous Reaction

Q. Which of the following processes WILL NOT be spontaneous at 1000 K? A)        ΔH = +40.2kJ/mole      ΔS =  -41.8 J/mole K B)        ΔH = +40.2kJ/...

Solved • Nov 16, 2016

Spontaneous Reaction

Q. Consider a 1.00 L solution of 0.150 M HCN (Ka = 4.9 * 10−10); Assume carbon is the central atom.  Indicate whether each statement is true or false...

Solved • Nov 10, 2016

Spontaneous Reaction

Q. Consider a reaction that has a positive ΔH and a positive ΔS. Which of the following statements is TRUE? A) This reaction will be non-spontaneous ...

Solved • Aug 29, 2016

Spontaneous Reaction

Q. For the chemical reaction, A → B, choose the combination that is correct.A) ΔG < 0; Q > KB) ΔG < 0; Q < KC) ΔG < 0; Q = KD) ΔG° <...

Solved • Aug 28, 2016

Spontaneous Reaction

Q. If a process has a ΔH = +48 kJ/mol and a ΔS = -130 J/mol K at what T will it become spontaneous? A) 298 K B) 273 K C) 369 K D) 642 K E) Never  

Solved • Aug 27, 2016

Spontaneous Reaction

Q. Sodium carbonate can be made by heating sodium bicarbonate: 2 NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g). Given that ΔH° = 128.9 kJ/mol and ΔG° = 33...

Solved • Aug 27, 2016

Spontaneous Reaction

Q. The thermodynamic condition for a spontaneous process at constant T and P is A) ΔS > 0. B) ΔS < 0. C) ΔG < 0. D) ΔG > 0. E) ΔG° = 0.

Solved • Aug 27, 2016

Spontaneous Reaction

Q. A spontaneous endothermic reaction always A) causes the surrroundings to get colder. B) bursts into flame. C) requires a spark to initiate it. ...

Solved • Aug 27, 2016

Spontaneous Reaction

Q. Which of the following is an example of a nonspontaneous process? A) ice melting at room temperature B) sodium metal reacting violently with wate...

Solved • Aug 27, 2016

Spontaneous Reaction

Q. The standard free energy of formation of CS 2 (l) is 65.27 kJ⋅mol −1 at 298 K. This means that at 298 K a) CS2 (l) will not spontaneously form C (...

Solved • May 17, 2016

Spontaneous Reaction

Q. When a liquid evaporates, which is true about the signs of the enthalpy and entropy changes? a) ΔH is positive, ΔS is postive b) ΔH is positive, ...

Solved • May 9, 2016

Spontaneous Reaction

Q. For the process O2 (g) → 2 O (g), ΔH ° = + 498 kJ. What would be predicted for the sign of ΔSrxn   and the conditions under which this reaction wou...

Solved • May 9, 2016

Spontaneous Reaction

Q. A particular chemical reaction has a negative ΔH and a positive ΔS. Which statement is correct?a) The reaction is spontaneous at all temperatures.b...

Solved • May 9, 2016

Spontaneous Reaction

Q. When solid NH4NO3 is dissolved in water at 25°C, the temperature of the solution decreases. What is true about the signs of ΔH and ΔS for this proc...

Solved • Apr 26, 2016

Spontaneous Reaction

Q. For each of the following chemical processes, state whether ΔS and ΔG are positive, negative,essentially zero, or undeterminable (based on the info...

Solved • Apr 19, 2016

Spontaneous Reaction

Q. When barium hydroxide is dissolved in water, the temperature of the solution increases. Which of the following statements regarding this dissolutio...

Solved • Apr 18, 2016

Spontaneous Reaction

Q. Which of the following statements is TRUE? (a) An exothermic process will always be spontaneous. (b) A process in which the entropy of the system...

Solved • Apr 18, 2016

Spontaneous Reaction

Q. Consider the following facts: water freezes spontaneously at -5 °C and 1 atm, and ice has a more ordered structure than liquid water. Explain how a...

Solved • Apr 18, 2016

Spontaneous Reaction

Q. Consider the following facts: water freezes spontaneously at -5 °C and 1 atm, and ice has a more ordered structure than liquid water. Explain how a...

Solved • Apr 18, 2016

Spontaneous Reaction

Q. Consider the reaction: 2O(g) → O2(g) a) Predict the signs of ΔH and ΔS. (There is no need to consult thermodynamic data tables).  b) Is the spont...

Solved • Apr 15, 2016

Spontaneous Reaction

Q. The plot of change in free energy versus temperature (T) shown below corresponds to a process that is enthalpically ________ (favored, disfavored) ...

Solved • Apr 15, 2016

Spontaneous Reaction

Q. Which of these processes is spontaneous?a) the combustion of natural gasb) a hot cup of tea cooling to room temperaturec) the extraction of iron me...

Solved • Apr 15, 2016

Spontaneous Reaction

Q. Kw for the auto-ionization of water, H2O(l) → H+(aq) + OH− (aq), is 1.0 × 10−14. What are the signs (+/−) of ΔS° and ΔH° for the reaction at 25°C? ...

Solved • Apr 13, 2016

Spontaneous Reaction

Q. Which reaction below is most likely spontaneous at any temperature?  a) CH3CH2OH (g) → CH3CH2OH (l) b) 2 H2 (g) + O2 (g) → 2 H2O (g) c) C6H6O6 (...

Solved • Mar 31, 2016

Spontaneous Reaction

Q. Which of the following statements are true? I. In a spontaneous process, the path between reactants and products is reversible. II. The reaction ...

Solved • Mar 31, 2016

Spontaneous Reaction

Q. The normal freezing point of ammonia is -78°C. Predict the signs of ∆H, ∆S, and ∆G for ammonia when it freezes at -80°C and 1 atm: NH3(l) → NH 3(s) 

Solved • Mar 29, 2016

Spontaneous Reaction

Q. The equilibrium constant for the reaction NH4Cl(s) → NH3(g) + HCl(g) is 1.1 × 10−16 at 25°C. If the equilibrium constant is 6.5 × 10 −2 at 300°C,...

Solved • Mar 29, 2016

Spontaneous Reaction

Q. Below what temperature does the following reaction become spontaneous?FeO(s) + CO(g)  → CO2(g) + Fe(g)    ∆H = -11.0kJ      ∆S = –17.4J/K191K632K29...

Solved • Mar 16, 2016

Spontaneous Reaction

Q. What factor ultimately determines whether any physical process, including a chemical reaction, is spontaneous or not? a) the change in entropy of ...

Solved • Mar 9, 2016

Spontaneous Reaction

Q. Which of the following is true regarding a non-spontaneous process:             I.    The process will occur with an outside influence           ...

Solved • Mar 9, 2016

Spontaneous Reaction

Q. The following reaction is endothermic:             2 H2O (l) → 2 H2 (g) + O2 (g) Which of the following answers correctly describes the spontanei...

Solved • Mar 9, 2016

Spontaneous Reaction

Q. For a reaction in which ΔH = 125 kJ/mol and ΔS = 325 J/K•mol, determine the temperature in Celsius above which the reaction is spontaneous. A.  38...

Solved • Mar 8, 2016

Spontaneous Reaction

Q. Given the following reaction: A(g) ⇌ B(g), the forward reaction is spontaneous under standard conditions. Which of the following statements must be...

Solved • Mar 7, 2016

Spontaneous Reaction

Q. The combustion reactions of hydrocarbons are reactions where ΔH°< 0 and ΔS° > 0. Based on this information, which one of the following statem...

Solved • Feb 23, 2016

Spontaneous Reaction

Q. A spontaneous chemical reaction is FAVORED by which of the following? a) increasing energy and increasing entropy b) lowering energy and increasi...

Solved • Feb 23, 2016

Spontaneous Reaction

Q. A spontaneous chemical reaction is FAVORED by which of the following? A. increasing energy and increasing entropy B. lowering energy and increasi...

Solved • Feb 21, 2016

Spontaneous Reaction

Q. Reactions with positive values of ∆S º r always become spontaneous at low temperatures. 1. False 2. True

Solved • Feb 21, 2016

Spontaneous Reaction

Q. For the reaction A + B ⇌ C + D, ΔH°= +40 kJ and ΔS°= +50 J/K. Therefore, the reaction at standard conditions is A. spontaneous at temperatures les...

Solved • Feb 21, 2016

Spontaneous Reaction

Q. A mixture of hydrogen and chlorine remains unreacted until it is exposed to ultraviolet light from a burning magnesium strip. Then the following re...

Solved • Feb 21, 2016

Spontaneous Reaction

Q. Consider the equation carefully, and think about the sign of ∆S for the reaction it describes. NH4Br (s) → NH3 (g) + HBr (g) ∆H = +188.3 kJ. Whic...

Solved • Feb 21, 2016

Spontaneous Reaction

Q. The sublimation of solid carbon dioxide is a spontaneous process. Predict the sign (+, -, or 0) of ∆Gº r , ∆Hº r , and ∆Sº r , respectively. 1. -,...

Solved • Feb 21, 2016

Spontaneous Reaction

Q. What is true for the following reaction under standard condition? C2H6 (g) → C2H4 (g) + H2 (g) ΔH° is 137 kJ and ΔS° is 120 J/K a) spontaneous a...

Solved • Feb 21, 2016

Spontaneous Reaction

Q. Which reaction below is most likely spontaneous at any temperature? a. CH3CH2OH (g) → CH3CH2OH (I) b. 2 H2 (g) + O2 (g) → 2 H2O (g) c. C6H6O6 (s...

Solved • Feb 10, 2016

Spontaneous Reaction

Q. A reaction has a standard entropy change of +32.83 J/K and a standard enthalpy of +8.10 kJ. At what temperature is the reaction spontaneous? Assume...

Solved • Feb 10, 2016

Spontaneous Reaction

Q. Which statement best describes spontaneous reactions? a) Spontaneous reactions occur very quickly b) Spontaneous reactions can proceed without an...

Solved • Feb 10, 2016

Spontaneous Reaction

Q. The following reaction is exothermic.                              N2 (g) + 3 H2 (g) → 2 NH3 (g) This means the reaction will be spontaneous i...

Solved • Feb 8, 2016

Spontaneous Reaction

Q. Hot and cold packs are commercially available for both medical treatment and food storage. Ammonium chloride, NH4Cl, is commonly used in cold packs...

Solved • Feb 2, 2016

Spontaneous Reaction

Q. Based on the following graph below, determine the signs for enthalpy and entropy, respectively.  

Solved • Feb 2, 2016

Spontaneous Reaction

Q. Which of the following is required for a spontaneous reaction:   A. The entropy of the universe increases. B. The enthalpy of the universe incre...

Solved • Feb 2, 2016

Spontaneous Reaction

Q. When ammonium ion and nitrate ion combine they form ammonium nitrate, NH4NO3. During this combination reaction the container feels cold to the touc...

Solved • Feb 2, 2016

Spontaneous Reaction

Q. The reaction between elemental nitrogen and elemental hydrogen, shown below, is most kinetically and thermodynamically favorable.         N2 (g) +...

Solved • Feb 2, 2016

Spontaneous Reaction

Q. For a certain chemical reaction,ΔH = 128 kJ/mol and ΔS = 64 J/ (mol × K) . What is the minimum temperature at which this reaction will be spontaneo...

Solved • Feb 2, 2016

Spontaneous Reaction

Q. If a reaction is exothermic but experiences a decrease in its entropy, under what conditions is the reaction most likely to be spontaneous?   A. ...

Solved • Feb 2, 2016

Spontaneous Reaction

Q. Consider the conversion of a substance from solid to liquid. Solid ⇌ Liquid  At one atmosphere pressure and at the melting point of the substance...

Solved • Feb 2, 2016

Spontaneous Reaction

Q. Above what temperature does the following reaction become spontaneous? FeO (s) + CO (g) CO2 (g) + Fe (g)                             ∆H = – 11.0 k...

Solved • Feb 2, 2016