Safety boundary
Use supplied graphs and calculations only. No new reactive chemistry is required.
Explicit chemistry instruction
Because ΔG=ΔH−TΔS, the entropy term grows in magnitude with temperature.
For some sign combinations, a process can switch from unfavorable to favorable as temperature changes.
The sign and units of ΔS must be handled carefully, often converting J to kJ.
Vocabulary: temperature; ΔS; sign; crossover; units.
Worked example
If ΔH=+30 kJ and ΔS=+0.10 kJ/K, ΔG becomes zero near T=300 K.
Guided question
Why can an endothermic process become favorable at sufficiently high temperature?
Independent work
- Solve two crossover-temperature problems.
- Audit ΔS units.
- Classify four sign combinations qualitatively.
Misconception check
Temperature does not affect every process in the same direction; signs of ΔH and ΔS matter.
Formative check
Which term carries explicit temperature dependence?
Reveal response
TΔS.
Mentor evidence conference
Ask Archaemenes to audit signs, units, thermodynamic conditions, and whether rate/direction are being kept distinct.
Teacher guidance
Foundation: Use a sign-quadrant chart.
Core: Interpret temperature dependence.
Extended: Solve crossover cases.