Which chemical is often used as a replacement for chlorine?

Sodium hypochlorite is frequently used as a replacement for chlorine, especially in water treatment and disinfection processes. It serves a similar function, acting as a powerful oxidizing agent that can effectively kill bacteria and other pathogens. This chemical is known for its ability to disinfect water by providing a source of chlorine without the potential negatives associated with handling gaseous chlorine.

Sodium hypochlorite is safer to store and handle compared to chlorine gas, making it a popular choice in various applications, such as swimming pool sanitation and municipal water treatment plants. Additionally, it breaks down into non-toxic substances, which is beneficial for environments where chemical residue is a concern.

In contrast, other chemicals mentioned in the choices have different primary uses: hydrogen peroxide is also a disinfectant but is more commonly used in lower concentrations and for specific applications; calcium carbonate is primarily a buffering agent or calcium supplement; ammonium sulfate is used mainly as a fertilizer and has no significant role as a chlorine substitute.