HTML version can be found at:
http://amasci.com/amateur/gold.html
WARNING: on 4/98 somebody bought some Astrobrights Goldenrod paper which
DID NOT WORK, it did not change colors. Therefor, run out and
buy reams of "goldenrod" quickly, before the "good" kind is
entirely replaced with the "useless" kind. Also, take some
baking soda to the stationery store, so you can test the paper
(the "good" kind will turn red when moist baking soda is rubbed
on it.)
--------------------------------------------------------------------
THE "GOLDENROD PAPER" SECRET (c)1996 William J. Beaty
Office supply stores and Kinko's copy centers sell a type of paper called
Astrobrights(tm) Galaxy Gold. It's "goldenrod" in color, sort of a
yellow/orange. Big deal. However, IF ALKALINE SUBSTANCES HIT IT, IT TURNS
MAGENTA! Spray it with Windex, and it instantly turns bright red! Cool!!
Astrobrights Galaxy Gold paper is the worlds largest acid/base indicator
strip. Dip it in a base solution (like ammonia cleaner, baking soda in
water, etc.) and it turns bright red. Dip it in acid (vinegar, lemon
juice, etc.) and it turns yellow again.
(Note: there are other brands of goldenrod which do not work. If in
doubt, wet a sample of the paper with ammonia glass cleaner. Kinko's
usually has bottles of Windex around)
The fact that an 8.5 x 11 sheet of goldenrod is enormously larger than
your typical acid/base test strip makes numerous classroom demonstrations
possible that never could be done before.
===========================================================================
TRY THESE:
Cut it into strips, dip it in acid or base. It turns colors. duh.
Dip it in base so it turns red, then dry it out. This gives you
acid-indicating paper which starts red and turns yellow.
Put dilute vinegar in one jar, baking-soda solution in another. (Baking
soda dissolves better in warm water.) Use paintbrushes to paint on the
goldenrod. Baking soda solution turns the yellow paper red. The vinegar
solution turns previously-reddened paper yellow. Paint an invisible
picture with vinegar on yellow goldenrod, let it dry, then spray it with
baking soda solution. It turns red everywhere except the places having
vinegar.
Draw "invisible" patterns or messages on the paper with rubber cement,
diluted Elmer's glue, transparent tape, etc., then spray it with alkaline
solution. The paper turns red except where your drawing has sealed it.
Yellow artworks on red background appears.
Wet a strip of previously-reddened goldenrod, then lower the strip into a
half-full glass of carbonated beverage. Don't let the strip touch the
liquid. The strip turns orange as the transparent pool of carbon dioxide
forms carbonic acid in the wet strip. This lets you "see" the invisible
pool of CO2 gas which fills the cup.
Dust your hands with baking soda. Claim that you have "Alien DNA Test
Paper," and if it turns red, it indicates that you are not human. Have
your audience put their thumbprints on some wet Goldenrod paper. Anyone with
baking soda on their fingers (you!) will leave a thumbprint which slowly
turns red.
ELECTROLYSIS: wet some goldenrod paper with salt water and place it on a
sheet of aluminum foil. Use clipleads to connect the positive terminal of
a 6v or 9v battery to the foil. Connect a wire to the negative battery
terminal. Now drag the negatvie wire across the wet goldenrod, and it turns
red. Write with electrochemistry! If you reverse the polarity of the
battery, you can erase your red drawings. If you replace the goldenrod
with previously-reddened paper, the reversed battery connections let you
draw in yellow on a red background
MY OLD ACID RAIN DEMO: Wet the inside of a glass jar. Light a match, blow
it out, then collect the smoke inside the upside-down jar. After awhile
the drops of water collect nasty combustion products from the smoke and
become acidic. Touch the drops to previously reddened goldenrod paper,
and it turns yellow, indicating acid. Instant acid rain! And might you
think twice about smoking cigarettes and putting acid in your lungs? I
thought up this one while working at the Museum of Science in Boston.
------------------------------------------------------------------
NOTE: Young kids shouldn't perform the following demonstrations.
Ammonia is somewhat toxic, is nasty if inhaled, and is dangerous
if splashed in eyes. Adult supervision only. Wear safety goggles.
------------------------------------------------------------------
AMMONIA DEMOS:
Wet some goldenrod paper, then drip some ammonia-based cleaner upon it.
Notice that the red drops have red haloes around them? Just the ammonia
fumes turn the paper red.
Wet some goldenrod paper. Put some ice cubes in a jar, then pour in a
little ammonia and wait for some cold ammonia gas to build up. Carefully
pour the transparent ammonia gas over the wet goldenrod paper, and it
flares red. Dip a wet strip of un-reddened goldenrod into the
seemingly-empty jar, and you'll discover the depth of the pool of cold
ammonia gas. Make wet marks on dry goldenrod, and when cold ammonia gas
is poured over it, the wet marks turn red.
Use a smoke-ring box to shoot invisible ammonia "smoke rings" at wet
goldenrod paper. Little red puffs appear where they hit.
Freak out Kinko's copy employees by buying one sheet of goldenrod, asking
for the bottle of glass cleaner, then yelling "look!" while spraying the
paper with the ammonia-based cleaner. But be warned, I've been doing
this for awhile, so the secret is spreading from Kinkos to Kinkos like a
mind-virus. They may already know about it.
-----------------------------------------------------------------------
The Goldenrod Paper Secret was passed on to me by Dr. Roy Gould of CFA,
who got it from his brother, an R&D chemist, who heard about it as the
"secret" traveled from chem lab to chem lab across the country.