More on baking soda composition
Lara Sternagle
Warren, Pennsylvania
Reference is made to the discussion in recent issues regarding the chemistry of deployed air bags. In “Is it baking soda?” (Letters to the Editor, April 1998), Philip Levy states that calcium is a major component of baking soda. This is incorrect. Baking soda is sodium bicarbonate, which consists of sodium, hydrogen, carbon, and oxygen–not calcium.
I do, however, agree with Levy`s challenge to James J. Onder`s assertion in “Rescue Guidelines for Air Bag-Equipped Vehicles” (December 1997) that “when irrigated with water, sodium hydroxide becomes harmless baking soda.” Actually, it becomes diluted sodium hydroxide. Carbon must be present (e.g., corn starch, carbon dioxide, and so on) in any chemical mechanism that could possibly form sodium bicarbonate.
