THE CHEMISTRY OF WATER
Wateris oneofthe simplestcompoundsand one of thecommonestonearth.
Indeed, more of theearth's surface is covered bywater than by land. The
humanbody itself is made up mostly of water.Thatis oneofthe reasons why
water is so essential to life, along with food and air.
Waterhas always fascinated men, but it was only in the relativelyrecent
pastthatthey discovered what it really was. TheancientGreeksthoughtthere
were only four elements andthatwater was one. Earth,fireandair were the
othersubstances they mistakenly called elements. Until the end ofthe 18th
century, everyone, including the most learned men, accepted this theory.Today
ofcourse we knowthatnone of these"elements"is really an element at all.
We knowthatwater is acompoundofhydrogenand oxygen andthatthe same
compoundcan exist as a solid (ice), a liquid (water) or a gas (water vapor).It
appearsmostcommonlyas a liquid, however, becausethatis its state ofmatter
within thetemperaturerange of 32 to 212^0 Fahrenheit.
In the following section you will discover foryourselfthatwater consistsof
hydrogenand oxygen, how the water drawn into cities from lakes and rivers is
made fit todrinkand what makes water"hard"or"soft."
HOW YOU CAN DECOMPOSE WATER BY ELECTROLYSIS
Gather thesematerials:Two piecesofcopperwire 12 inches long and 2 pieces
4 incheslong;2 dry cells;sodiumchloride(NaCI);2 strips ofaluminumfoil,
tby 3 inches in size; 2 testtubes;and aquartglassjaror anywide-mouthed
container.
Follow this procedure: 1.Look at thediagramon page 35 andarrangeyour
materialsin the same way. If you follow thesedirectionscarefully and check
each step with thediagram,you will have notrouble.Set up your apparatus
in exactly this way:
Attachone strip ofaluminumfoil to one end of a l2-inchlength ofcopper
wire.
Connectthe free endofthecopperwire to thecentralterminalof one dry
cell.