The word
"alkali" is meaning the calcined
ashes (see calcinations), referring to the original source of alkaline
substances. A water-extract of burned plant ashes, called potash and composed mostly of potassium carbonate, was
mildly basic. After heating this substance with calcium
hydroxide (slaked
lime), a far more strongly basic substance known as caustic potash (potassium
hydroxide) was produced. Caustic potash was
traditionally used in conjunction with animal fats to produce soft soaps, one of the caustic processes that rendered soaps from
fats in the process of saponification, one known since antiquity. Plant potash lent the name to the element
potassium, which was first derived from
caustic potash, and also gave potassium its chemical symbol K (from the German name
Kalium), which ultimately derived from alkali.
QUIZ !!!!!
1- What does alkali mean ?
2- Why is alkali dangerous ?
3- What are they used for ?
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