baking soda; sodium bicarbonate
Abbreviation of 重炭酸曹達 (じゅうたんさんそうだ). Common in cooking and cleaning contexts.
See also: 重炭酸ソーダ
I use baking soda to make the cake fluffy.
I use baking soda to deodorize the fridge.
重曹 refers specifically to baking soda (sodium bicarbonate), one of the substances that ソーダ can loosely denote.
Abbreviation of 重炭酸曹達 (じゅうたんさんそうだ), an older term for sodium bicarbonate.