The Adventures of Rascal the Cessna

Which is more important? Being a female and opinionated or being human and focusing on accuracy of language. It wasn’t spontaneous as the conditions in which the water began to boil didn’t arrive instantly and without warning. #mansplainingisthedumbestthingiveeverheard

'Spontaneous' in chemistry has a different meaning than it does in everyday vocabulary. In this context it is used to describe a process that occurs without an outside force changing the enthalpy (heat) or entropy of the reaction. It has nothing to do with how quickly the reaction occurs; some naturally occurring spontaneous reactions can take hundreds of years or more (such as rocks being changed to different kinds of rock via pressure). Since the presence of a vacuum here is what caused the water to boil, rather than raising the temperature (changing the enthalpy), the process of the water boiling is a spontaneous one. Jessica Meir was correct and accurate in her language, but I can understand the mix-up. My source is the chemistry for engineers class I had to take last semester, and there are plenty of chem textbooks I could dig up to reference if needed.