Final answer:
A reaction can be spontaneous at certain temperatures depending on the enthalpy and entropy changes.
Step-by-step explanation:
In general, a reaction is spontaneous if the standard free energy change, ΔG, is negative. This means that the reaction can occur on its own without any external energy input. However, the statement that a reaction is not spontaneous at any temperature is false. There are cases where a reaction may not be spontaneous at certain temperatures, but becomes spontaneous at other temperatures. The spontaneity of a reaction depends on both enthalpy and entropy changes.
For example, there are reactions that are favored thermodynamically (have negative ΔG) but are not spontaneous at low temperatures due to the unfavorable entropy change. Conversely, there are reactions that are favored entropically (have positive ΔS) but are not spontaneous at high temperatures due to the unfavorable enthalpy change. Therefore, it is not accurate to say that a reaction is not spontaneous at any temperature.