Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy AS. Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction A B с observations This reaction is slower below 18. °C than above. This reaction is spontaneous only above 97. °C. This reaction is always spontaneous, but proceeds faster at temperatures above 72. °C. AH is ΔS is conclusions AH is AS is AH is AS is ✓ (pick one) positive negative unknown (pick one) ✓ (pick one) ✓ (pick one) (pick one)

Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy AS. Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction A B C to deduce the signs of AH... observations This reaction is endothermic and proceeds slower at temperatures below 14. °C. This reaction is always spontaneous, but proceeds slower at temperatures below 110. °C. This reaction is spontaneous only above -37. °C. ΔΗ is AS is AH is AS is ΔΗ is AS is conclusions X (pick one) (pick one) (pick one) (pick one) (pick one) (pick one) (pick one) positive negative unknown 4 Maria

Try Again Your answer is incorrect. Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy AS. Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction A reaction C: Your answer is incorrect. B с observations This reaction is spontaneous except below - 16. °℃ but proceeds at a faster rate above 133. °C. This reaction is always spontaneous, but proceeds slower at temperatures above 23. °C. The reverse of this reaction is always spontaneous but proceeds slower at temperatures below -50. °C. AH is As is conclusions AH is AS is AH is AS is X positive positive ↑ î negative î positive ŵ positive Ś ↑ positive ↑

For the synthesis of nitrogen dioxide, NO2: 2N2(g) + O2(g) 2NO2(g) this reaction has the energy diagram shown. What is the spontaneity of the reaction? Reaction coordinate Enthalpy

A. Predict the sign of AS', if possible, for each of the following reactions. If you cannot predict the sign for any reaction, state why. (2pts each) a) C2H2(g) + 2 H2(g) → C2H6(g) b) N2(g) + O2(g) → 2 NO(g) c) 2 C2H2(g) + 3 Oz(g) → 4 CO(g) +2 H2O(g) d) 2 C(s) + O2(g) → 2 COg) e) N2H4() → N2(g) +2 H20(g) f) C2H;OH() + 3 O2(g) → 2 CO2(g) + 3 H20() g) Pa(s) + 5 O2(g) → PO10(s) h) 2 NaHCO3(s) → NazCO3(s) + H20(g) + CO2(g)

Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy AS. Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction A B с observations This reaction is always spontaneous, but proceeds faster at temperatures below 25. °C. This reaction is spontaneous except above 49. °C. The reverse of this reaction is always spontaneous but proceeds faster at temperatures above 93. °C. AH is AS is conclusions AH is AS is AH is AS is X (pick one) (pick one) (pick one) (pick one) (pick one) (pick one) S î ↑ î ↑

Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy AS. Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction A B C observations This reaction is spontaneous only above -7. °℃ but proceeds at a faster rate above 23. °C. This reaction is spontaneous except above -46. °C. This reaction is always spontaneous, but proceeds slower at temperatures below 79. °C. ΔΗ AS is AH is AS is conclusions AH is AS is X ✓ (pick one) ↑ positive negative unknown (pick one) (pick one) (pick one) (pick one) S ↑ ↑ ↑

What is the change in Gibb's Free Energy for a reaction that has an enthalpy change of -270.8 kJ/mol and a entropy change of 550.9 J/(mol K) at 44.7 °C? Your Answer: Answer units

Use the observations about each chemical reaction in the table below to decide the sign

Try Again Your answer is incorrect. Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy AS. Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction A reaction B: Your answer is incorrect. B с observations This reaction is always spontaneous, but proceeds faster at temperatures above 9. °C. This reaction is spontaneous except below -20. °℃ but proceeds at a slower rate below 73. °C. Crystallization of a pure compound is spontaneous only below - 16. °C. AH is AS is conclusions AH is AS is AH is AS is X negative ↑ positive ↑ positive î negative ↑ negative ↑ negative ↑ 5