What happens when you mix baking soda and heat?

When baking soda (sodium bicarbonate) is heated, it undergoes a chemical reaction called thermal decomposition. This reaction breaks down the baking soda into sodium carbonate, water vapour, and carbon dioxide gas. The chemical equation for this reaction is:

2NaHCO3 (baking soda) → Na2CO3 (sodium carbonate) + H2O (water vapour) + CO2 (carbon dioxide gas)

The decomposition of baking soda is an endothermic reaction, which means that it absorbs heat from the surroundings. This is why baking soda is often used as a leavening agent in baking, as it releases carbon dioxide gas which causes the baked goods to rise.

The rate at which baking soda decomposes increases as the temperature increases. This is why baking soda is typically used in recipes that require high temperatures, such as cakes and cookies.

When baking soda is heated to a very high temperature, it can also undergo a second chemical reaction called calcination. This reaction breaks down the sodium carbonate into sodium oxide and carbon dioxide gas. The chemical equation for this reaction is:

Na2CO3 (sodium carbonate) → Na2O (sodium oxide) + CO2 (carbon dioxide gas)

Calcination is an exothermic reaction, which means that it releases heat to the surroundings. This is why baking soda can sometimes be used as a source of heat in chemical reactions.