Baking powder is a mixture of ingredients, and it behaves very differently. ✖️ What’s in Baking Powder

  It contains:
      Sodium bicarbonate (baking soda)
      One or more acidic salts (e.g. monocalcium phosphate, sodium aluminum sulfate)
      Sometimes a starch to keep it dry and stable
      

Also read https://bakeschool.com/focus-on-baking-soda/