This document provides instructions for creating zinc chromate pigment through a chemical reaction. A yellow solution of sodium or potassium chromate is mixed with a zinc sulfate or zinc chloride solution, producing a yellow-orange color. The addition of sodium hydroxide changes the solution to basic and bright yellow as zinc chromate precipitate forms. The precipitate is then filtered and allowed to dry, producing the final zinc chromate pigment.

1. CHROME
YELLOW
SCIENCE
3rESOAC
Neus Pepió
Zutoia Niñerola

2. All the materials
that you need

3. 1. Pour 5 mL of a
0.5 M solution of
sodium or
potassium
chromate into a
beaker.
Record the color
of the solution in
your notebook

4. Add 5mL of a 0.5 M
solution of zinc sulfate
or zinc chloride to the
beaker and stir the
two solutions together

6. Test the pH with either pH or litmus paper. Add 6M
NaOH drop wise to make the solution basic and mix
well. The color will change from yellow-orange to
bright yellow.

8. Gravity filter the
precipitate of zinc
chromate.

9. Allow the pigment to dry uncovered on the
filter paper on your bench until next week.