Question : What chemical is added to washing powders to keep them dry ?

(1) Sodium perborate

(2) Sodium carbonate

(3) Sodium sulphate

(4) None of these

Answer : in all above options the correct answer is “(3) Sodium sulphate ” , it means the Sodium sulphate (Na₂SO₄) is the substance which can be used as as detergent filler it means it is used in washing powders to keep them dry or to protect washing powders from moisture , because if the washing powders absorbing moisture than it can be bad for it. that is why Sodium sulphate (Na₂SO₄) is mixed in detergent .

Explanation of answer : Sodium perborate is used as de-stain substance in washing powder , it means it used to clean the cloths or we can say it is able to remove marks or sports from the cloths and bring whiteness on cloths , in shorts it used as whitening agents in washing powder.

Sodium carbonate is also cleaning agent especially in hard water. so this is also not used to keep them dry , but Sodium sulphate chemical is added to washing powders to keep them dry that is why we have marked this option correct answer. it meaning is that Sodium sulphate (Na₂SO₄) acts like silica gel and hence keeps washing powders free from moisture.