Potassium permanganate is a substance used for disinfecting water. Here's why:
- Disinfecting Water: Potassium permanganate is commonly used as a water disinfectant. It has strong oxidizing properties that help in killing bacteria, viruses, and other harmful microorganisms present in water.

- Oxidizing Agent: Potassium permanganate acts as an oxidizing agent, which means it can accept electrons from other substances and cause them to undergo oxidation. This property helps in breaking down organic matter and destroying pathogens in water.

- Broad-Spectrum Disinfection: Potassium permanganate is effective against a wide range of microorganisms, including bacteria, viruses, fungi, and parasites. It can help in preventing the spread of waterborne diseases.

- Simple Application: Potassium permanganate can be easily applied to water for disinfection. It is available in crystal or powder form, and a small amount can be dissolved in water to create a disinfecting solution.

- Safe to Use: When used in appropriate concentrations, potassium permanganate is considered safe for disinfecting water. However, it is important to follow recommended guidelines and not exceed the recommended dosage.

In conclusion, potassium permanganate is a substance commonly used for disinfecting water due to its strong oxidizing properties, broad-spectrum disinfection capabilities, and ease of application.