An endothermic process that involves an increase in system entropy is spontaneous when temperature is:

1. Enthalpy and entropy pull in opposite directions here. 2. This condition describes an endothermic process that involves an increase in system entropy. 3. Both its enthalpy and entropy changes are positive, so they share an arithmetic sign. 4. A process with matching signs exhibits a temperature-dependent spontaneity. 5. Raising the temperature lets the entropy term dominate, so the process becomes spontaneous. _Source: OpenStax Chemistry 2e (CC BY 4.0), Ch 16 'Thermodynamics', sections 16.1-16.4_