Appearance: White solid, deliquescent ; White hygroscopic solid in various forms ; Odorless, white or slightly yellow lumps, rods, flakes, sticks, or pellets. [Note: May be used as an aqueous solution.]
Appearance: White powder ; Colourless crystals or white powder ; White, odorless powder. [Note: Readily absorbs CO2 from the air to form calcium carbonate.]