If you have a reaction that changes one mole of gas into two moles of gas, will the entropy of the system increase, decrease or remain the same? Justify your answer in terms of the definition of chemical state given above. Exercises Fill in the chart below: Change Sign of Sign of ΔS ΔH Evaporation Condensation Sublimation (solid to gas) Deposition (gas to solid) Melting Freezing Decomposition to atoms Formation of a compound from atoms A hot piece of metal is dropped into a cool glass of water. What is the sign of for the metal? What is the sign ΔS of for the water? ΔS Determine for each of the following reactions if is positive, negative, or approximately zero. ΔS CaCO3 (s) CaO (s) + O2 (g) → 2 NO2 (g) N2O4 (g) → Fe2O3 (s) + 3 CO (g) 2 Fe (s) + 3 CO2 (g) → CF4 (g) + 2 Br2 (l) CBr4 (l) + 2 F2 (g) → KClO4 (s) KCl (s) + 2 O2 (g) → 6 CO2 (g) + 6 H2O (l) C6H12O6 (s) + 6 O2(g) → 2 H2O2 (l) 2H2O (l) + O2 (g) → NaCl (s) + H2O (l) Na+ (aq) + Cl– (aq) → (Solid sodium chloride dissolves in water)
If you have a reaction that changes one mole of gas into two moles of gas, will the entropy of the system increase, decrease or remain the same? Justify your answer in terms of the definition of chemical state given above. Exercises Fill in the chart below: Change Sign of ΔS Sign of ΔH Evaporation Condensation Sublimation (solid to gas) Deposition (gas to solid) Melting Freezing Decomposition to atoms Formation of a compound from atoms A hot piece of metal is dropped into a cool glass of water. What is the sign of ΔS for the metal? What is the sign of ΔS for the water? Determine for each of the following reactions if ΔS is positive, negative, or approximately zero. CaCO3 (s) → CaO (s) + O2 (g) 2 NO2 (g) → N2O4 (g) Fe2O3 (s) + 3 CO (g) → 2 Fe (s) + 3 CO2 (g) CF4 (g) + 2 Br2 (l) → CBr4 (l) + 2 F2 (g) KClO4 (s) → KCl (s) + 2 O2 (g) 6 CO2 (g) + 6 H2O (l) → C6H12O6 (s) + 6 O2(g) 2 H2O2 (l) → 2H2O (l) + O2 (g) NaCl (s) + H2O (l) → Na+ (aq) + Cl– (aq) (Solid sodium chloride dissolves in water)
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