South Pasadena Chemistry Name

South Pasadena • Chemistry Name Period Date 5 · Chemical Reactions H O L I D A Y C H E M I S T R Y

Ornament Lab 1. Galvanized iron is Iron (symbol ____) coated 8. Oxidation: with the active metal, ______(____). the charge is more ______(positive/negative) electrons are ______(gained/lost) 2. Iron rusts, which means it combines with oxygen and water. Reduction: Iron(II) oxide = ______the charge is more ______(positive/negative) Iron(III) oxide = ______electrons are ______(gained/lost)

3. Rust flakes off the surface of iron exposing more iron for corrosion. Zinc, forms zinc oxide 9. Fe + O2  Fe2O3 ______, that stays on the surface and What is oxidized? _____  _____ protects the metal. What is reduced? _____  _____ 4. Write the balanced equation for the reaction when the ornament was placed in the beaker of 3M HCl. 10. Zn + 2HCl  ZnCl2 + H2(g) What is oxidized? _____  _____ What is reduced? _____  _____

2+ 2+ 5. Write the balanced equation for the reaction 11. Fe + Cu  Cu + Fe when the Q-tip of Cu2+ touched the exposed What is oxidized? _____  _____ iron surface. What is reduced? _____  _____

6. Sketch one side of your ornament here: Chemist’s Tree Demo 12. Copper wire (_____) is placed in a solution of silver nitrate (______)

13. The reaction is:

14. What is oxidized? _____  _____ What is reduced? _____  _____

Oh Chemist’s Tree, Oh Chemist’s Tree, 7. When you look at your ornament, you can see Thou copper limbs are silvery. brown areas that are ______( ____) When silver gains electrons free, and shiny areas that are ______(____). No longer ion will they be.

The copper’s metal… sweet and nice, But silver steals its electrons… twice. Oh Chemist’s Tree, Oh Chemist’s Tree, Form copper ions, oxidatively. South Pasadena • Chemistry Name Period Date 5 · Chemical Reactions O R N A M E N T L A B

1. Put on your goggles.

2. Use a razor blade or X-acto knife to cut out your design. The exposed areas will eventually be dark. The covered areas will remain shiny and silvery.

The Chemistry:

3. Lower the ornament into the yellow hydrochloric acid (3M) solution. Bubbles will form on the surface. When the rapid bubbling is finished (3-5 minutes) use tongs to remove the ornament to a paper towel. Do not rinse… yet.

4. Dip a Q-tip into the blue copper sulfate solution. Paint the exposed iron metal surface with the solution. A copper color appears. Hint: If the copper color does not appear, or is uneven, placing the ornament back into the acid solution. Placing the ornament into the rinse water may also help. Experiment.

5. Briefly rinse the ornament in the tray of water.

Finishing:

6. Remove the blue tape (please throw the tape away… don’t leave it on the lab table). Hold your ornament by the edges… the copper can be rubbed off.

7. Round off the sharp corners using the tin snips over the green tray.

8. Have your teacher drill a hole in the ornament for you.

9. Open a paper clip into an “S” shape and hang your ornament so it can be sprayed LIGHTLY with the clear acrylic spray.

10. Hang your ornament on the string to dry. It only takes a few minutes. Look around your lab area to make sure you have cleaned up your mess.