Articles

    The Art of Bleaching

    Kids, people use liquid laundry bleach to remove unwanted color, in other words stains, from clothes. This bleach is a 5% solution of sodium hypochlorite in water. It also removes color from other materials and we will use this today to produce some interesting effects. First of all though, you must do this with an adult partner because of the care that must be taken when handling bleach. So get your adult partner, a bottle of laundry bleach, colored construction paper, spoons, brushes, cotton swabs, steel wool, and drinking glasses.

    Please note:  All chemicals and experiments can entail an element of risk, and no experiments should be performed without proper adult supervision.

    The colors of construction paper quickly disappear with the application of bleach. The trick is to apply and spread bleach in a manner that will result in an artistic pattern. Pour a small amount of bleach into a glass, and then experiment with different applicators, such as a spoon, brush, and cotton swab. Spread the bleach around on the paper by folding, tilting, and blowing through a straw. A little bit of bleach goes a long way, and you'll be able to see the patterns almost immediately. Let your work of art dry before hanging it up for all to see.

    In this case the bleaching action can also be called an "oxidizing" reaction. You can prove that oxygen is made from bleach by putting two small balls of steel wool (of the same size) into two different glasses. Cover them with equal amounts of water. Add a tablespoon of vinegar to each glass, and then to just one of them also add a tablespoon of bleach. After about half an hour the steel wool without bleach should be unchanged, but the ball with the bleach should be very rusty. Rust is iron (from the steel wool) that has combined with oxygen in the presence of water. While iron rusts easily, it happens very quickly here because the bleach is producing so much oxygen!

    [SAFETY NOTES: Do not leave children unattended while working with bleach. Do not let the bleach come into contact with skin or eyes; if it does flush immediately with large amounts of water. Thoroughly clean or dispose of all materials that came in contact with bleach.]

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    Kathleen Carrado Gregar, PhD, Argonne National Labs 
    [email protected]
    May 1996

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    Reference: Mr. Wizard's Supermarket Science, by Don Herbert, Random House: NY, 1980, pg. 45.