Q4

CHE 184 Brevard College QUESTION 2. Predict if the following chemical changes will occur with an increase or decrease in entropy without using numerical calculations. Explain your reasoning (10 points). a) Thermal decomposition of calcite: CaCO3(s) → CaO (aq) + CO2(g) -> b) Metabolic combustion of glucose in your brain while trying to solve this homework: C6H12O6(s) + 6 O2(g) →6 CO2(g) + 6 H2O(g).

Identify the change in phyical state that is a decrease in entropy.   water boiling   ice melting   water evaporating   water freezing

which statement about entropy is true? non-spontaneous reactions sometimes will happen all by themselves entropy stops when pure substances are in solid state the entropy of the universe is increasing during a change of state there is no change in entropy

Which of the following is not true of spontaneity?     It happens without the addition of external energy     It can occur faster in the presence of a catalyst.     It occurs due to the dispersal of energy and matter.     It is usually unidirectional.     It requires external forces to proceed.

When the temperature-time data graph was reviewed, it was found that an error had been made in determining ΔT. Instead of 4.76 °C, ΔT was actually 4.70 °C. Based on this change only, calculate the correct ΔH neutralization for the reaction of NH3, and acetic acid.

Consider the following reaction: H2 + Br2  →. HBr ΔH = -43 kcal/mol ΔS = 0.0272 kcal/mol   What is the ΔG value for the reaction at 300 K?

Short answers please

Read the descriptions of physical or chemical changes in the table below. Then decide whether the change will be spontaneous, if you can. Change A solid absorbs heat and turns to a gas. During an exothermic chemical reaction, a solid is consumed and a gas produced. Is this change spontaneous? Yes. No. Can't decide with information given. ○ Yes. ○ No. Can't decide with information given. An endothermic chemical reaction between two liquids results in gaseous products. Yes. No. ○ Can't decide with information given.

Read the descriptions of physical or chemical changes in the table below. Then decide whether the change will be spontaneous, if you can. Change During an endothermic chemical reaction, four moles of gaseous reactants are turned into two moles of gaseous products. A solid precipitates from a solution, releasing heat as it does so. A solid absorbs heat and turns to a gas. Is this change spontaneous? Yes. O No. O Can't decide with information given. O Yes. O No. O Can't decide with information given. O Yes. O No. O Can't decide with information given.

Please don't provide handwriting solution

For each of the processes, determine whether the entropy of the system is increasing or decreasing. The system is underlined. Entropy is increasing Entropy is decreasing Answer Bank a snowman melts on a spring day a water bottle cools down in a refrigerator iron rusts to iron oxide a document goes through a paper shredder dissolved sugar precipitates out of water to form rock candy

5. The change in enthalpy for a certain reaction is a small, positive number. The change in entropy for this reaction is an extremely large positive number. Is this reaction exergonic or endergonic?exergonic  endogonic

Question 12 of 14 > Consider the following chemical reaction. 2 CH,(g) +30,(g) 2CO(g) + 4 H,O(1) Select all the statements that are correct. The potential energy of the reactants is higher than the potential energy of the products. The reactants can adopt a larger number of configurations than the products. The reaction should become more product favored at high temperatures. The reactants can adopt a fewer number of configurations than the products. The potential energy of the reactants is lower than the potential energy of the products. The reaction should become more product favored at low temperatures. Incorrect

Classify each of the statements as true or false. True False A reaction will have an equilibrium constant that is greater than one if The entropy of a substance increases when a solid melts into a liquid at AG° for the reaction is negative. any temperature. For an endothermic reaction, an increase in temperature results in an An endothermic reaction is never spontaneous. increase in the equilibrium constant. Product formation is always favored in a reaction with a positive AH° Entropy increases as the temperature decreases. and a negative ASº.

#5 Q5

In which is there a positive entropy change? A. Magnesium combusts in air to form Magnesium oxide B. Condensation of steam C. Dry ice sublimates D. Nitrogen and hydrogen pas reacts to form gaseous ammonia

How many of the following processes are accompanied by a positive entropy change? heating a pot of water spilling a glass of milk dissolving sugar in water making ice cubes melting an icicle Group of answer choices 1 2 4 3 5

Which of the following describes the entropy change in the given reaction? 2 C₁₂O(g) →2 Cl2(g) + 7 O̟₂(g) A B C E The entropy change is negative because a larger molecule (C₁₂O) is converted into two smaller molecules (CI, and O₂). The entropy change is zero because the reactants and products are all gases. The entropy change cannot be determined because the temperature is not specified. The entropy change is negative because there are more moles of products than reactants. The entropy change is positive because there are more moles of products than reactants.

Consider the reaction: CaCO3(s) ↔ CaO(s) + CO2(g) The reaction enthalpy and entropy are: ΔHo rx = -117.1 kJ∙mol-1; ΔSo rx = -362 J∙K-1mol-1. Assume that these values are independent of temperature.   If this reaction is in equilibrium and the temperature is increased, what do you expect will happen? Write one of the following: net reaction to right, net reaction to left, no net reaction and explain your reasoning. Do not use Le Chatelier’s Principle

32) Which reaction is accompanied by an increase in entropy? A) C8H16() + 12 O₂(g) → 8 CO₂(g) + 8 H₂O(1) B) Ba(OH)₂ (s) + CO₂(g) → BaCO3(s) + H₂O(l) C) NH4NO₂ (s)→→ N₂(g) + 2 H₂O(1) D) 2 C₂H₂(g) + 5 O₂(g) → 4 CO₂(g) + 2 H₂O(s) E) N₂(g) + 3 H₂(g) → 2 NH3(g) mion sonste

Chp 19 #28 & # 30

Now calculate the change in entropy (delta S) for the following reaction, using the thermodynamic tables  2 C4H10 (g)  +  13 O2 (g)   →    8 CO2 (g)  +  10 H2O (g)   a. 312 J/K b. none of these c. – 312 J/K d. – 113 J/K e. 515 J/K f. 402 J/K g. – 402 J/K h. 113 J/K i. – 515 J/K

For each of the following reactions, indicate whether you would expect the entropy change of each of these systems will increase or decrease or it is in its equilibrium state. Write A if it will increase, B for decrease, and C for equilibrium. • N2O4(g) → 2NO2(g) • CH3OH(l) → CH3OH(g) • 2HCl(g) → H2(g)+Cl2(g) • 4 Al(s)+3O2(g) → Al2O3(s) • 2KClO3(s) → 2KCl(s)+3O2(g) • 2H2O2(aq) → 2H2O(aq)+O2(g) • NaCl(s) + H2O(l) → Na(aq)+Cl(aq) • Cooling one mole of ideal gas • Expanding a gas into a vacuum

Calcium ΔHof (kJ/mol) ΔGof (kJ/mol) So (J/mol K) Ca (s) 0 0 41.4 Ca (g) 178.2 144.3 158.9 Ca2+ (g) 1925.9     CaC2 (s) -59.8 -64.9 70.0 CaCO3 (s, calcite) -1206.9 -1128.8 92.9 CaCl2 (s) -795.8 -748.1 104.6 CaF2 (s) -1219.6 -1167.3 68.9 CaH2 (s) -186.2 -147.2 42.0 CaO (s) -635.1 -604.0 39.8 CaS (s) -482.4 -477.4 56.5 Ca(OH)2 (s) -986.1 -898.5 83.4 Ca(OH)2 (aq) -1002.8 -868.1 -74.5 Ca3(PO4)2 (s) -4126.0 -3890.0 241.0 CaSO4 (s) -1434.1 -1321.8 106.7 CaSiO3 (s) -1630.0 -1550.0 84.0       Carbon ΔHof (kJ/mol) ΔGof (kJ/mol) So (J/mol K) C (s, graphite) 0 0 5.7 C (s, diamond) 1.9 2.9 2.4 C (g) 716.7 671.3 158.1 CCl4 (l) -135.4 -65.2 216.4 CCl4 (g) -102.9 -60.6 309.9 CHCl3 (l) -134.5 -73.7 201.7 CHCl3 (g) -103.1 -70.3 295.7 CH4 (g) -74.8 -50.7 186.3 CH3OH (g)…

Answer question numbers 7-8 and 9

Consider the following process: water boiling in a steam kettle no change in the entropy of the system an decrease in the entropy of the system an increase in the entropy of the system