Embed Size (px)
Citation preview
Chapter 14 Thermodynamics
Spontaneous Processes, Entropy,
and Free Energy
Copyright McGraw-Hill 2009
Entropy Changes in a System
• Ssolid < Sliquid
Copyright McGraw-Hill 2009
Entropy Changes in a System • Sliquid < Svapor
Copyright McGraw-Hill 2009
Entropy Changes in a System
• Spure < Saqueous
Copyright McGraw-Hill 2009
Entropy Changes in a System
Slower temp < Shigher temp
Copyright McGraw-Hill 2009
Entropy Changes in a System
• Sfewer moles < Smore moles
Predict whether ΔS is positive or negative for each of the following processes 1. Freezing liquid bromine
Copyright McGraw-Hill 2009
ΔS<0
Predict whether ΔS is positive or negative for each of the following processes 1. Freezing liquid bromine 2. Evaporating a beaker of ethanol at room
temperature
Copyright McGraw-Hill 2009
ΔS<0
ΔS>0
Predict whether ΔS is positive or negative for each of the following processes 1. Freezing liquid bromine 2. Evaporating a beaker of ethanol at room
temperature 3. Dissolving sucrose in water
Copyright McGraw-Hill 2009
ΔS<0
ΔS>0 ΔS>0
Predict whether ΔS is positive or negative for each of the following processes 1. Freezing liquid bromine 2. Evaporating a beaker of ethanol at room
temperature 3. Dissolving sucrose in water 4. Cooling nitrogen gas from 80°C to 20°C
Copyright McGraw-Hill 2009
ΔS<0
ΔS<0
ΔS>0 ΔS>0
Predict whether ΔS is positive or negative for each of the following processes 1. Freezing liquid bromine 2. Evaporating a beaker of ethanol at room
temperature 3. Dissolving sucrose in water 4. Cooling nitrogen gas from 80°C to 20°C 5. 2KClO4(s) è 2KClO3(s) + O2(g)
Copyright McGraw-Hill 2009
ΔS<0
ΔS<0
ΔS>0 ΔS>0
ΔS>0
Predict whether ΔS is positive or negative for each of the following processes 1. Freezing liquid bromine 2. Evaporating a beaker of ethanol at room
temperature 3. Dissolving sucrose in water 4. Cooling nitrogen gas from 80°C to 20°C 5. 2KClO4(s) è 2KClO3(s) + O2(g) 6. H2O(g) è H2O(l)
Copyright McGraw-Hill 2009
ΔS<0
ΔS<0
ΔS<0
ΔS>0 ΔS>0
ΔS>0
Predict whether ΔS is positive or negative for each of the following processes 1. Freezing liquid bromine 2. Evaporating a beaker of ethanol at room
temperature 3. Dissolving sucrose in water 4. Cooling nitrogen gas from 80°C to 20°C 5. 2KClO4(s) è 2KClO3(s) + O2(g) 6. H2O(g) è H2O(l) 7. 2Na(s) + 2H2O(l) è 2NaOH(aq) + H2(g)
Copyright McGraw-Hill 2009
ΔS<0
ΔS<0
ΔS<0
ΔS>0 ΔS>0
ΔS>0
ΔS>0
Predict whether ΔS is positive or negative for each of the following processes 1. Freezing liquid bromine 2. Evaporating a beaker of ethanol at room
temperature 3. Dissolving sucrose in water 4. Cooling nitrogen gas from 80°C to 20°C 5. 2KClO4(s) è 2KClO3(s) + O2(g) 6. H2O(g) è H2O(l) 7. 2Na(s) + 2H2O(l) è 2NaOH(aq) + H2(g) 8. CH4(g) + 2O2(g) è CO2(g) + 2H2O(l)
Copyright McGraw-Hill 2009
ΔS<0
ΔS<0
ΔS<0
ΔS<0
ΔS>0 ΔS>0
ΔS>0
ΔS>0
Predict whether ΔS is positive or negative for each of the following processes 1. Freezing liquid bromine 2. Evaporating a beaker of ethanol at room
temperature 3. Dissolving sucrose in water 4. Cooling nitrogen gas from 80°C to 20°C 5. 2KClO4(s) è 2KClO3(s) + O2(g) 6. H2O(g) è H2O(l) 7. 2Na(s) + 2H2O(l) è 2NaOH(aq) + H2(g) 8. CH4(g) + 2O2(g) è CO2(g) + 2H2O(l) 9. N2(g) è 2N(g)
Copyright McGraw-Hill 2009
ΔS>0
ΔS<0
ΔS<0
ΔS<0
ΔS<0
ΔS>0 ΔS>0
ΔS>0
ΔS>0
Catabolism is the degradative phase of metabolism in which organic nutrient molecules (carbohydrates, fats and proteins) are converted into smaller, simpler end products.
Catabolic pathways release energy, some of which is conserved in the formation of ATP and reduced electron carriers (NADH, NADPH, and FADH2); the rest is lost as heat.
Anabolism, or biosynthesis, small, simple precursors are built up into larger and more complex molecules, including lipids, polysaccharides, proteins, and nucleic acids.
Anabolic reactions require an input of energy, generally in the form of the phosphoryl group transfer potential of ATP and the reducing power of NADH, NADPH, and FADH2.
Copyright McGraw-Hill 2009
ATP-ADP Interconversions
Endergonic Does not occur
spontaneously
Exergonic
The coupling of exergonic and endergonic reactions through a shared intermediate is central to the energy exchanges in living systems.
