Sodium hypochlorite is usually purchased at 12% to 12.5% and is then distributed down to a more stable percentage of ______.

Sodium hypochlorite is usually purchased at 12% to 12.5% and is then distributed down to a more stable percentage of ______.

• A. 8%
• B. 4%
• C. 5%
• D. 6%

Answer: (D)

Sodium hypochlorite is unstable and decomposes more quickly at higher concentrations, especially when exposed to heat, light, or metals. Diluting the stock solution from about 12% to a lower, common distribution level makes it easier to store, handle, and feed into chlorine dosing systems, while also slowing the rate of chlorine loss. A 6% solution hits a practical balance: it remains relatively stable in storage and transport, yet is strong enough to provide effective disinfection when dosed correctly. That’s why 6% is the standard distribution concentration. Higher concentrations would decompose faster and be harder to manage, while much lower concentrations would require larger volumes to achieve the same disinfection, making 6% the most convenient and reliable choice in many plants.

Sodium hypochlorite is unstable and decomposes more quickly at higher concentrations, especially when exposed to heat, light, or metals. Diluting the stock solution from about 12% to a lower, common distribution level makes it easier to store, handle, and feed into chlorine dosing systems, while also slowing the rate of chlorine loss. A 6% solution hits a practical balance: it remains relatively stable in storage and transport, yet is strong enough to provide effective disinfection when dosed correctly. That’s why 6% is the standard distribution concentration. Higher concentrations would decompose faster and be harder to manage, while much lower concentrations would require larger volumes to achieve the same disinfection, making 6% the most convenient and reliable choice in many plants.