Redox Reactions

• Redox=reduction-oxidation

• Redox Reactions=reduction-oxidation reactions

Do you know Bleaching Processes ?

Removing colored components from a textile. Common bleaches are hydrogen peroxide, sodium hypochloride, and sodium chlorite. 2) The brightening and delignification of pulp by the addition of oxidizing chemicals such as chlorine or reducing chemicals such as sodium hypochloride

Redox In Bleaching Processes

By group “koala”

The Knowledge In The Textbook

Bleach can be used to remove stains from clothing. Actually, it does not remove the chemicals

in stains from the fabric, it reacts with them to form

colorless compounds. After the reaction, the stains are

removed and the clothing will be clean.

The equation for this redox reaction is:

Bleacher can change the color of the food and they Inhibit bacterial growth. In the food processing, they are extensive used. For peroxidebleaches, practical application is little. As for hydrogen Oxide, only be permitted in somewhere to retain freshness for cow’s milk, dried beancurd, not be used for peroxidebleaches.

How can we get bleaches2Ca(OH)2+2Cl2

Ca(ClO)2+CaCl2+H2O* Calcium hypochlorite is the main

component of bleaches*Bleaches cannot be stored with

sunshine directlyCa(ClO)2+H2O+CO2

CaCO3↓+2HClO*If bleach is exposed to the sun, it will

lose its function.

Chlorine Bleach

• Chlorine bleach is a 5.25% solution of sodium hypochloride and the most powerful. The liquid version is the most common but a dry form is also available. Both must be diluted with water for safe use on fabrics.

• Chlorine bleach should always be added to the washer water and mixed in well before adding clothes. Never pour bleach directly onto fabrics. If using bleach for stain removal, bleach the entire garment to prevent spotting.

• When chlorine bleach is used in the wash, it acts as a disinfectant on bacteria and viruses and generally whitens fabrics. Liquid chlorine bleach has a limited shelf life. If more than six months old, it may have no effect on stains and should be replaced.

Oxygen Bleach

• Oxygen bleach is often called All-Fabric Bleach and is usually safe for all fabrics and colors. It works more slowly than chlorine bleach and may contain sodium perborate or sodium precarbonate.