Our chemistry
experiment will determine which pennies will be more reactive with
hydrochloric acid.
Procedure
Put on safety apparel. Cut
both pennies in half, and put a penny in each beaker with the
hydrochloric acid.Leave the pennies in the beakers for at
least 2 hours. After the time is up use the tongs to retrieve the
pennies out of the beakers and compare the cores.
Conclusion
The zinc core of the post 1984
penny was eaten by the hydrochloric acid. The pre 1984 penny just
got cleaner.
Questions &
Answers
Q.
Why did the acid eat the
middle out of one penny and not the
other?
Q. Why did the pennies have to
be cut in half?
Q. Why did the acid turn
yellow while eating the
pennies?
Carl Wilhelm Scheele was born in
Stralsund, Germany, and as a boy became a pharmacist's assistant. He
later opened his own pharmacy shop in Koping, Sweden, and made most
of his discoveries there.
Scheele was the Swedish chemist
who discovered chlorine and prepared oxygen. He did not publish his
work in time, and Joseph Priestley, an English Scientist, received
credit.
Scheele was the first to obtain
pure lactic, oxalic, citric, and hydrofluoric acids. He discovered
Scheele's green, molybdenum, and scheelite.
Carl Wilhelm Scheele discovered
oxygen, chlorine, manganese, and other chemical substances and
compounds through extensive experimentation.
In 1774 various events took place
such as:
The American theater was
suspended after an order declared by the Continental Congress
stated that the colonies "discountenance and discourage" all horse
racing and all kinds of gaming, cock fighting, exhibitions of
shows, plays and other expensive diversions and
entertainments.
Abraham Werner introduced a
classification of minerals.
First Continental Congress was
formed in America to increase communication within the
colonies.
