Sodium Cromate, For Industrial

Sodium Chromate can be prepared from chromite (Fe(CrO2)2) ore by treating sodium carbonate. Sodium chromate is hygroscopic. It absorbs moisture in air to give tetrahydrate. It is easily dissolves in water to give yellow chromate ions. Addition of a dilute acid will shift the above equation to the right and the solution turns from yellow to orange. However, addition of an alkaline solution will shift the equation to the left, turning the solution from orange to yellow. Between two extremes it is possible for both chromate and dichromate ions to coexist in proportion according to the value of the pH.