Bleaching Powder: What Is It and How to Use It
Bleaching powder, also known as calcium hypochlorite, is a white or yellowish solid that is used for water treatment and as a bleaching agent. It has a strong smell of chlorine and decomposes slowly in moist air. Bleaching powder is the main active ingredient of commercial products called chloride of lime or chlorinated lime.
Bleaching powder has various applications in sanitation, organic chemistry, and household cleaning. Here are some of the common uses and benefits of bleaching powder:
- It can sanitize public swimming pools and disinfect drinking water by killing bacteria and viruses.
- It can act as a general oxidizing agent in organic chemistry, for example, to synthesize chloroform or dichloromethane.
- It can remove stains and whiten fabrics, paper, and teeth by breaking down organic molecules that cause discoloration.
- It can clean and deodorize surfaces such as countertops, floors, and toilets by removing dirt, grease, and odors.
However, bleaching powder also has some drawbacks and risks that should be considered before using it. Here are some of the precautions and limitations of bleaching powder:
- It can irritate the skin, eyes, and respiratory tract if inhaled or contacted. It can also cause burns or blisters if used in high concentrations or for prolonged periods.
- It can react with other chemicals such as ammonia, acids, or metals to produce toxic or explosive gases. It can also corrode metal pipes or fittings if used in water systems.
- It can lose its effectiveness over time due to exposure to light, heat, or moisture. It can also decompose into calcium chloride and calcium carbonate, which can leave residues or harden the water.
- It can damage or discolor some materials such as silk, wool, leather, or colored fabrics if used improperly or excessively. It can also bleach out natural colors or dyes from hair, skin, or plants.
Therefore, bleaching powder should be used with care and according to the instructions on the label. It should be stored in a cool, dry, and dark place away from children and pets. It should be diluted with water before using it for cleaning or disinfecting purposes. It should be rinsed off thoroughly after use and disposed of safely. It should not be mixed with other cleaners or chemicals unless specified otherwise.
Here are some of the steps to use bleaching powder for different purposes:
How to Use Bleaching Powder for Water Treatment
Bleaching powder can be used to purify water for drinking or swimming by killing harmful microorganisms and removing impurities. Here are the steps to use bleaching powder for water treatment:
- Measure the amount of water to be treated and the amount of bleaching powder required. The recommended dosage is 2 grams of bleaching powder per 1000 liters of water.
- Dissolve the bleaching powder in a small amount of water in a bucket or a container. Stir well until no lumps remain.
- Add the solution to the water to be treated and mix well. Allow the water to stand for at least 30 minutes before using it.
- Test the chlorine level of the treated water using a chlorine test kit or strips. The ideal chlorine level is between 0.2 and 0.5 ppm (parts per million). If the chlorine level is too high, add more water to dilute it. If the chlorine level is too low, add more bleaching powder solution and repeat the process.
- Store the treated water in a clean and covered container away from sunlight and heat. Use the water within 24 hours or boil it before using it.
How to Use Bleaching Powder for Organic Chemistry
Bleaching powder can be used as an oxidizing agent in organic chemistry to synthesize various compounds such as chloroform or dichloromethane. Here are the steps to use bleaching powder for organic chemistry:
- Wear appropriate protective equipment such as gloves, goggles, and lab coat. Work in a well-ventilated area and use a fume hood if possible.
- Prepare a solution of bleaching powder in water in a round-bottom flask. The concentration of bleaching powder depends on the reaction and the desired product. For example, to make chloroform from acetone, use 10 grams of bleaching powder per 100 mL of water.
- Add the organic compound to be oxidized to the bleaching powder solution and stir well. The amount of organic compound depends on the reaction and the desired product. For example, to make chloroform from acetone, use 10 mL of acetone per 100 mL of bleaching powder solution.
- Heat the mixture gently using a water bath or a heating mantle until the reaction is complete. The reaction time and temperature depend on the reaction and the desired product. For example, to make chloroform from acetone, heat the mixture at 50Â°C for 30 minutes.
- Cool the mixture and separate the organic layer from the aqueous layer using a separatory funnel or a pipette. The organic layer contains the product and some impurities. The aqueous layer contains excess bleaching powder and by-products.
- Purify the organic layer by washing it with water, drying it with anhydrous sodium sulfate, and distilling it under reduced pressure. The purified product can be collected in a receiver flask and stored in a dark bottle away from heat and light.