Assertion: sodium carbonate | /r/HasProperty | added
Facets:
value: over a four minute period
type: TEMPORAL
Source sentences:
text: The soda ash and distilled water are then added to the cylinder and then mls. of 75% phosphoric acid solution are added over a four minute period.
text: Water is softened on a large scale by the addition of just enough lime to precipitate the calcium as carbonate and the magnesium as hydroxide, whereupon sodium carbonate is added to remove the remaining calcium salts.