Why do spontaneous reactions still require energy (activation energy)?
A reaction is spontaneous at a particular temperature. That’s why there is a T in the equation for Gibb’s free energy. DG = DH – TDS Suppose a reaction is spontaneous at room temperature. There may be a temperature, below which the reaction is not spontaneous. Don’t confuse activation energy and temperature. They are not the same thing. This statement is not quite right, “…reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, often coming about only after the input of some type of energy…”. I hope it doesn’t actually say that. A reaction which is spontaneous needs no ADDITIONAL energy to occur. The available energy is sufficient to make the reaction occur, and not additional energy need be added. The statement should say, “… reactions can be either spontaneous, requiring no additional input of energy, or…” A reaction that is nonspontaneous at some temperature may be spontaneous at an elevated temperature because the T in DG must be greater so th
