How to Turn Baking Soda Into Washing Soda (Sodium Bicarbonate to Sodium Carbonate)

Make Washing Soda From Baking Soda
It’s easy to make washing soda from baking soda. Chemically, the difference between baking soda and washing soda is the hydration level of the molecule.

Baking soda and washing soda are two handy household chemicals. You may be able to find washing soda (soda ash) with laundry supplies at the store, but if you can’t find it, this is one chemical that’s super easy to make from baking soda.

Make Washing Soda

  1. Pour baking soda into a cookie sheet. Spread it out to form a layer.
  2. Bake the soda at 400°F (200°C) for 30 minutes to 1 hour. The time isn’t critical. You can’t ‘overcook’ the soda, but you want to be sure to drive off all the water.
  3. Remove the pan from heat, allow the washing soda to cool, and store it in a sealed container to keep it from picking up moisture from the air.

How It Works

Baking soda is sodium bicarbonate (NaCHO3), while washing soda is sodium carbonate (Na2CO3). When you heat baking soda, water (H2O) and carbon dioxide (CO2) are driven off, leaving you with washing soda.

2NaHCO3 → Na2CO3 + H2O + CO2

This is the second step of the Solvay process. The Solvay process is a commercial method of making sodium carbonate from sodium chloride, ammonia, carbon dioxide, and water (brine, limestone, and ammonia) that forms sodium bicarbonate as an intermediate.

Things to Do With Washing Soda

Once you have washing soda, what do you do with it?

  • Washing soda can be used on its own as a gentle, non-toxic, non-scratch cleaner.
  • Mix a bit of washing soda with water to form a paste to help lift grease or burn marks from pots and pans. Avoid using this treatment on aluminum pans or surfaces.
  • Use sodium carbonate to help remove hard water stains, clean tile and grout, and remove soap scum from tubs.
  • You can add 1/2 cup to a load of laundry to help brighten whites and remove odors.
  • Because it’s alkaline, you can rub some in as a pre-treatment for greasy stains. However, don’t leave it on too long or it may affect colors or damage delicate fabrics. Another method is to add washing soda to the laundry pre-soak cycle. Add a cup of washing soda to the load and let it soak about 20 minutes before continuing to the regular wash cycle.