Results:The color disappeared from the cloth. The reaction between the
calcium chlorate and nitric acidproducedhypochlorousacid (HClO), which in
turncaused the bleaching. Theequationfor this reaction is:
2CaOC1 2 +2HNOa-+CaCl 2 +Ca(NOa)2+2HCIO
Hypochlorousacid is a chemical from whichnascentoxygen can be set free.
Nascent oxygen is oxygen in its atomic form before it has had time to combine
into molecules of02'Itis a very unstable substance and tries to combine with
other atoms or molecules quickly. Here is theequationshowing the releaseof
nascent oxygen:
HCIO-+HCl+°
Because the nascent oxygen is so quick to combine with otheratoms or
molecules, it combines almostinstantlywith the complex dye molecules in the
cloth. In doing so, it changes the dyes to colorless compounds. Thatis why
the cloth lost its color.
:. Mostnaturalfibers, such ascottonand linen, have a yellowish look when
they are firstmanufacturedbecauseofthe presence ofnaturalimpurities. They
must be bleached to pure white before they can be dyed, printed, or sold as white
fabrics. The commercial process of bleaching these fabrics is very similar to
the process you used in this experiment.
The"home"methodofbleaching is to use chlorine water, which is chemically
similar to hypochlorous acid. Care must be taken when bleaching stains from
colored cloths, because the dye might be removed as well as the stain. Only
cotton,linen, and heavy canvas-type cloth can be bleached successfully with
chlorine water.
HOW YOU CAN MAKE SOAP AND DISCOVER HOW IT CLEANSGather thesematerials:Coconutor olive oil; a solutionofsodium hydroxide
(NaOH);an alcoholburner;a smallpot;a tablespoon;a glass stirringrod;a
small,amountof kerosene or gasoline; salad or mineral oil; some cigarette
lighter fluid; magnesium sulfate(MgS0 4 ) ;and 8 test tubes.
Follow thisprocedure:I. Put 4 tablespoonfulsofcoconut or olive oil into the
small pot and add I test tubeful of sodium hydroxide solution to it. Carefully
heat the liquid over the alcohol burner, using a small flame. Stir the mixture
constantlyand continue heating it until it becomes a thick paste.CAUTION:
Be sure you wear goggles. Sodium hydroxide burns skin and spoils clothing. If
any sodium hydroxide gets on your skin, wash it immediately with cool water.
Relember,too, that the pot should never again be used for cooking.
.. 1:t!tepaste cool~ndrinse it. withwate:t.oremo~e all the excess sodium
hy .xide. You may either use this paste as ItISor let It dry and becomehard.