Lye and caustic soda are common names for which substance?

Lye and caustic soda are indeed common names for sodium hydroxide, which is a strong alkaline substance. Sodium hydroxide, with the chemical formula NaOH, is widely used in various applications, including cleaning agents, soap making, and as a chemical precursor in many industrial processes. Its strong basicity allows it to effectively neutralize acids and saponify fats, making it versatile in both household and industrial settings.

In contrast, sodium bicarbonate, potassium hydroxide, and calcium hydroxide are distinct chemical compounds with different properties and uses. Sodium bicarbonate (baking soda) is milder and commonly used in baking and as an antacid. Potassium hydroxide is another strong base but is primarily used in specific applications such as fertilizers and biodiesel production. Calcium hydroxide, often referred to as lime, is used in construction and water treatment. Therefore, sodium hydroxide is accurately identified as the substance commonly referred to as lye or caustic soda.