Active disinfectant propey of bleaching powder is mainly due to formation of:
**Core Concept**
Bleaching powder, a common disinfectant, owes its efficacy to the formation of hypochlorous acid (HOCl) and hypochlorite ions (OCl-) upon contact with water. These compounds are responsible for the antimicrobial properties of bleaching powder.
**Why the Correct Answer is Right**
The active disinfectant properties of bleaching powder are primarily attributed to the formation of hypochlorous acid (HOCl) and hypochlorite ions (OCl-). These compounds are potent antimicrobial agents that disrupt microbial membranes, denature proteins, and inactivate enzymes, ultimately leading to the death of microorganisms. The formation of HOCl and OCl- occurs when bleaching powder (calcium hypochlorite) reacts with water, releasing hypochlorous acid, which then dissociates into hypochlorite ions.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the formation of hydrochloric acid (HCl) is not responsible for the active disinfectant properties of bleaching powder. While HCl is a byproduct of the reaction, it does not contribute to the antimicrobial activity.
**Option B:** This option is incorrect because the formation of calcium chloride (CaCl2) is a result of the reaction between bleaching powder and water, but it does not possess antimicrobial properties.
**Option C:** This option is incorrect because the formation of oxygen gas (O2) is not directly related to the active disinfectant properties of bleaching powder.
**Clinical Pearl / High-Yield Fact**
Remember that hypochlorous acid (HOCl) is a potent disinfectant that is also used in other applications, such as wound cleaning and water purification. Its antimicrobial properties make it an effective agent against a wide range of microorganisms, including bacteria, viruses, and fungi.
**Correct Answer: D. Hypochlorous acid (HOCl) and hypochlorite ions (OCl-).**