Redox Reaction of Copper and Silver

Lab Techniques

• Measuring mass

• Transferring liquids

Materials

• 15 cm bare copper wire

• Filter paper

• Test tube

• Test tube stand

• Petri plate

• Stirring rod

• Wash bottle

• 50-ml beaker

• 50-ml graduated cylinder

• Small funnel

• Silver nitrate (AgNO3)

• Distilled water

Precautions

• Wear safety goggles, rubber gloves, face mask and lab coat; silver nitrate will stain clothes and skin. Flush with water in the event of contact.

• Handling silver nitrate solutions will lead to black stains where it is spilled. It is also poisonous. Be especially careful to avoid getting it in the eyes.

Procedure

1. Obtain a 15 cm length of bare copper wire and coil it around a pencil, forming a loose coil or "spring" on one end. Stretch the coil to reach from the bottom to the top of the tube. The other end should reach to the top of your test tube and be uncoiled.

2. Make a hook on one end of the spring for weighing.

3. Weigh the coil as accurately as possible with the available balance. Place the copper wire in the test tube.

4. Weigh ~1.5 grams of silver nitrate in your beaker.

5. Weigh a piece of filter paper for use in separating the silver later.

6. Pour 20 mL of distilled water into your beaker. Use a stirring rod to stir until completely dissolved. To avoid stains, be sure to rinse the stirring rod with distilled water before setting it down.

7. Add the silver nitrate solution into the test tube containing the copper wire. Rinse the beaker and rod with distilled water, adding this rinse to the test tube.

8. Note any evidence for reaction in the tube.

9. Set the tube aside until the reaction is completed (~2 hours).

10. After the reaction is complete, shake the wire and dislodge the silver allowing it to fall to the bottom of the test tube.

11. Any silver that adheres to the wire can be rinsed back into the solution by squirting it with a stream of water from the wash bottle of distilled water. You may wish to use a beaker to wash the wire.

12. Pour off the blue solution through the filter paper into the waste beaker, being sure to keep the silver precipitate in the test tube. Rinse with distilled water and decant several times to wash the silver. Finally wash onto a filter paper. If a beaker was used to wash the wire, be sure to wash the contents of the beaker into the filter collecting silver.

13. Allow filter paper to dry until next meeting.

14. Weigh the copper coil during the next class period, if necessary.

15. Cool the filter paper to room temperature.

16. Weigh the silver and filter paper.

17. Be sure you have all the data carefully recorded.

Activity

Data:

1. Mass of copper coil before the reaction,g

______________

2. Mass of copper coil after the reaction, g

______________

3. Mass of copper reacted, g

______________

4. Mass of filter paper, g

______________

5. Mass of filter paper + silver, g

______________

6. Mass of silver produced by the reaction, g

______________

Calculations and Discussions:

1. Find the number of moles of silver produced.

2. Find the number of moles of copper consumed during the reaction.

3. Find the mole ratio of copper to silver in this reaction (round to the nearest whole number).

4. Write a balanced equation for the reaction using the mole ratio derived above as the coefficients.

5. During the middle ages, a group of people called alchemists searched unsuccessfully for a way to "transmute" or change one element to another, e.g. lead to gold. Was the copper "transmuted" into silver in this experiment? Explain.

Just wanna share this activity we perform two years ago, I enjoyed doing it, you can also do it if you're interested about the topic. Comment your thoughts and queries below.

@CLANDESTINE0819