"The salt is white."
Translation:La sal es blanca.
When we say something is "feminine" and the word only has one form (unlike words like "gato/gata" (cat)) it has no real meaning aside of it needing the feminine words (articles, adjectives and such) to accompany it. It does not mean the salt is male or female or anything XD It is just a grammar think, no need to go deeper, it just is as it is! ;]