EXPERIMENT
Magic Inks
Visitors write their initials by applying three different clear
solutions to separate pieces of paper. Each solution is an
invisible “ink.” Each ink is paired with another clear solution
that acts as the “developer.” After allowing the solutions to
dry, visitors apply the corresponding developer solutions and
observe the results. For one of the inks, a third solution acts
as an “anti-developer,” reversing the original chemical
reaction.
OBJECTIVES:
Visitors learn that reactions between different chemicals can create
a color change and that different reactions produce different colors.
They also learn that there are practical and commercial uses for
some chemical reactions.
SCIENCE TOPICS
PROCESS SKILLS
VOCABULARY
Chemical Reactions
Observing
Acid
Products of Chemical
Reactions
Comparing/Contrasting
Investigating
Base
Chemical Reaction
Properties of Solutions
Indicators
Hypothesizing
Indicator
Solution
Acids and Bases
Unit 6 The Chemistry of Toys
Experiencing Chemistry ©2007 OMSI
U6.1
Experiment: Magic Inks
Operating Guide
(with amounts to have on hand)

Five 100-ml plastic storage bottles

5 large test tubes with rack

5 one-hole stoppers

5 non holed stoppers

cloth tipped swabs (keep 20 on hand)

100 sheets of scrap paper, approximately 2 in. by 2 in.

Phenolphthalein (an indicator; keep 15 g on hand)

Five 250-ml plastic beakers

Sharpened pencils (keep four on hand)

Magic pens (CrayolaTM Secret Writers or GaltTM Magic Pens)
(keep three on hand)

Colored developer pens (CrayolaTM Secret Writers or GaltTM Magic
Pens) (keep eight on hand)

95% C2H5OH (ethyl alcohol or ethanol) (keep 2 liters on hand)

FeCl3 (ferric chloride) (keep 25 g on hand)

KSCN (potassium thiocyanide) (keep 25 g on hand)

1M HCl (hydrochloric acid) (keep 500 ml on hand)
— OR — keep 500 ml concentrated (12.1M) HCl on hand

1M NaOH (sodium hydroxide) (keep 500 ml on hand)
— OR — keep 100 g solid NaOH on hand
Setup/Takedown Procedures
 With one color, label three large test tubes “Magic Ink 1,” “Developer
1,” and “Anti-Developer 1.”
 With another color,label two large test tubes “Magic Ink 2” and
“Developer 2.”
 Label the five cotton swabs to match the bottles and insert into
stoppers.
 Label the small box “Paper.”
 Label the plastic tub or beaker “Used Paper.”
 Label the three plastic beakers “Magic Pens,” “Developer Pens,” and
“Pencils.”
 Label the magic pens “Magic Pens.”
 Label the developer pens “Developer Pens.”
U6.2
Unit 6 The Chemistry of Toys
Experiencing Chemistry ©2007 OMSI
Experiment: Magic Inks
Operating Guide
 Get alcohol solutions (Developer 1 and 2 and Magic Ink 2) from the
flammables cabinet (see Materials Prep), 0.5M HCl (hydrochloric acid)
from the acid cabinet, and 0.5M NaOH (sodium hydroxide) solution
from the hydroxide cabinet.
 If any solutions are low, prepare more (see Materials Prep) (keep 50
ml of each solution on hand)
 Set out the visitor instructions in the Plexiglas holder.
 On a tray, set out the following:

Five large test tubes ordered by colored labels in rack

Labeled beakers with two magic pens, two developer pens,
and two pencils

A labeled box full of scrap papers

A labeled beaker for used paper
 Sharpen the pencils.
 Remove the rubber stoppers from the tubes. Fill each tube about 1/3
with the appropriate solution. Insert the appropriate stopper with
cotton swab into each bottle.
 If the scrap paper is low, cut more pieces, approximately 2 in. by 2 in
 Replace any soiled cotton swabs.
 Discard all used paper.
 Return all equipment to the tub.
 Switch out stoppers on test tubes for ones with no holes.
 Return the alcohol solutions (Developers 1 and 2 and Magic Ink 2) to
the flammables cabinet.
 Return NaOH (sodium hydroxide) to the hydroxides cabinet.
 Return HCl (hydrochloric acid) to the acids cabinet.
 Clean the tray and leave it at the station.
◊
Fill the test tubes with a very small amount of solution, to avoid
wasting solution if contamination occurs. If any of the solutions in the
tubes become contaminated (change color), rinse out the bottle and
refill it with fresh solution.
◊
Make sure inks are dry before using developers.
Unit 6 The Chemistry of Toys
Experiencing Chemistry ©2007 OMSI
U6.3
Experiment: Magic Inks
◊
Operating Guide
Check the setup frequently to make sure the caps are on the pens
and all swabs are in appropriate bottles.
Ghost WriterTM and Magic PenTM pens have a different chemical
reaction from the CrayolaTM and GaltTM pens.
HCl (hydrochloric acid) and NaOH (sodium hydroxide) are hazardous
substances; follow handling and disposal instructions.
Consult Material Safety Data Sheets (MSDS) for additional
information.
To prepare Developer 1, 0.5% phenolphthalein solution in C2H5OH (ethyl alcohol):
 Weigh 0.5 g of dry phenolphthalein.
 Add 100 ml of 95% C2H5OH .
 Store in labeled/dated 100-ml plastic storage bottle in flammables
cabinet.
To prepare Magic Ink 1, 0.5M NaOH (sodium hydroxide) solution:
 Measure 50 ml of 1M NaOH.
 Add 50 ml dH2O (deionized water).
 Store in labeled/dated 100-ml plastic storage bottle in hydroxides
cabinet.
To prepare Anti-Developer 1, 0.5M HCl (hydrochloric acid) solution:
 Wear protective eyewear, chemical safety gloves, and an apron or lab
jacket.
 Measure 50 ml 1M HCl.
 Add 50 ml dH2O (deionized water).
 Store in a labeled/dated 100-ml bottle in the acids cabinet.
To prepare Magic Ink 2, 2% KSCN (potassium thiocyanide) alcohol solution:
 Weigh 2 g KSCN (potassium thiocyanide).
 Add 100 ml C2H5OH.
U6.4
Unit 6 The Chemistry of Toys
Experiencing Chemistry ©2007 OMSI
Experiment: Magic Inks
Operating Guide
 Store in a labeled/dated 100-ml plastic storage bottle in the
flammables cabinet.
To prepare Developer 2, 2% FeCl3 (ferric chloride) alcohol solution:
 Weigh 2 g FeCl3 (ferric chloride).
— OR — 3.3 g FeCl3  6H2O (ferric chloride hydrate).
 Add 100 ml C2H5OH.
 Store in a labeled/dated 100-ml plastic storage bottle in the
flammables cabinet.
To prepare stock solution 1.0M NaOH (sodium hydroxide):
CAUTION: concentrated or solid NaOH (sodium hydroxide) is
extremely corrosive. Handle it with care. Wear protective
gloves, apron, and eyewear. Avoid contact with skin or clothing.
CAUTION: a large amount of heat will be evolved after you mix
NaOH with water. Do not handle the beaker until it has cooled.




Weigh 40 g solid NaOH.
Add 1000 ml dH2O (deionized water).
Mix to dissolve the ingredients.
Store in a labeled and dated 1000-ml plastic bottle in the hydroxide
cabinet
To prepare 1.0M HCl (hydrochloric acid):
CAUTION: concentrated HCl (hydrochloric acid) is extremely
corrosive. Handle it with care. Wear protective gloves, apron, and
eyewear. Use only in the fume hood. Avoid contact with skin or
clothing. Neutralize any spills with baking soda and clean with
copious amounts of water.
CAUTION: A large amount of heat will be evolved after you mix HCl
with water. Do not handle the beaker until it has cooled.
 Turn on the fume hood.
 Wear protective eyewear, chemical safety gloves, and an apron or lab
jacket.




In the fume hood, measure 83 ml of concentrated (12.1M) HCl.
Add the acid to 917 ml of dH2O (deionized water) to make one liter.
Store any extra solution in a labeled/dated bottle in the acid cabinet.
Turn off the fume hood.
Unit 6 The Chemistry of Toys
Experiencing Chemistry ©2007 OMSI
U6.5