Final answer:
The active ingredient in common household bleach, or chlorine bleach, is sodium hypochlorite (NaOCl), which is a powerful oxidizer widely used for its disinfecting and bleaching properties.
Step-by-step explanation:
The main active ingredient in common household bleach, often referred to as chlorine bleach, is sodium hypochlorite (NaOCl). Bleach is typically a pale greenish-yellow dilute solution used widely as a disinfectant or a bleaching agent. The sodium hypochlorite in bleach acts as a powerful oxidizer and is known for its ability to decompose, releasing chlorine, which is the compound responsible for the bleaching and disinfecting effects.
Special bleaching powders may contain compounds that serve as precursors to release sodium hypochlorite, which is the classical household bleaching agent. Sodium hypochlorite is also involved in various disinfecting purposes and is a cost-effective agent found in many cleaning products. Therefore, the correct answer to the question is option 2) NaOCl.