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.

 

Despite the fact that the oxidation state of chromium in both chromate and dichromate is +6, sodium chromate is not as strong oxidizing agent as the dichromate. However, the former can be used to precipitate metal chromates (in alkaline solution)

 

The red-brown silver(I) chromate can be dissolved in strongly ionized acids such as sulfuric and nitric acids but are insoluble in those which are feebly ionized such as ethanoic acid (CH3COOH)