Which of the following is not the use of washing soda?
(i) Manufacture of glass, soap and paper
(ii) As a cleaning agent for domestic purposes
(iii) For removing permanent hardness of water
(iv) Baking cake

Correct option is D

The correct answer is (D) Baking cake .

one which is not a use of washing soda:

Manufacture of glass, soap, and paper:

• Correct. Washing soda (sodium carbonate) is used in the manufacturing process of glass, soap, and paper. In glassmaking, it helps lower the melting point of silica, in soap, it acts as a cleaning agent, and in paper manufacturing, it's used in the pulping process.

As a cleaning agent for domestic purposes:

• Correct. Washing soda is used as a cleaning agent for various domestic purposes, such as cleaning laundry and removing stains.

For removing permanent hardness of water:

• Correct. Washing soda is used to soften water by removing calcium and magnesium ions, which cause permanent hardness.

Baking cake:

• Incorrect. Washing soda is not used for baking cakes. Baking soda (sodium bicarbonate), not washing soda, is used as a leavening agent in baking.

Thus, the Baking cake, as washing soda is not used in baking cakes.

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