碳酸氢钠
Sodium bicarbonate is one of the main components of the common "black snake" firework. The effect is caused by the thermal decomposition, which produces carbon dioxide gas to produce a long snake-like ash as a combustion product of the other main component, sucrose. Sodium bicarbonate is also used to delay combustion reactions by releasing CO2 and H2O when heated, both of which are flame retardants.