"Sodium hydroxide"Sodium hydroxide, "sodium carbonate"sodium carbonate, "sodium biphosphate"sodium biphosphate, "sodium fluoride"sodium fluoride, are all crystalline materials. And they dissolve in aqueous solutions to give quantities of HO^(-)HO−. In the case of NaOHNaOH, the quantity is stoichiometric. Ammonia, NH_3NH3, exists as a gas before dissolution in water.