Introduction
The purpose of the lab was to find which metal is the most reactive and which metal is the least reactive. It was known before the experiment that the metals used in the experiment are placed in the activity series from most active to least active as follows: magnesium, aluminum, zinc, and copper.
The hypotheses formed were that zinc nitrate would react with aluminium and magnesium; aluminium nitrate would react with magnesium; copper nitrate would react with zinc, magnesium, and aluminium; and magnesium nitrate would not react with any metals.
Materials
- 0M zinc nitrate
- 0M aluminum nitrate
- 0M copper nitrate
- 0M magnesium nitrate
- Pipettes(4)
- Copper wire
- Aluminum wire
- Magnesium ribbon
- Zinc metal strips
- Sandpaper
- Microscale reaction plate
Procedure
- Use a pipette to fill each of the four wells in column 1 of the reaction plate with 2mL of 1.0M aluminium nitrate solution.
- Repeat the procedure in step 1 to fill the four wells in column 2 with 2mL of 1.0M magnesium nitrate solution.
- Repeat the procedure in step 1 to fill the four wells in column 3 with 2mL of 1.0M zinc nitrate solution.
- Repeat the procedure in step 1 to fill the four wells in column 4 with 2mL of 1.0M copper nitrate solution.
- With sandpaper, polish 10cm of aluminium wire until it is shiny. Use scissors to cut the aluminium wire into four 2.5-cm pieces.
- Place a piece of the aluminium wire in each row; A well that contains the solution.
- Repeat the procedure from step 5 using 10cm of magnesium ribbon. Place the ribbon in each row well that contains the solution.
- Use sandpaper to polish small strips of zinc metal. Place a piece of zinc metal in each row C well that contains the solution.
- Repeat the procedure from step 5 using 10cm of copper wire. Place the pieces in each row D well that contains the solution.
- Observe what happens in each cell. After five minutes, record your observations on the data table you made.
Results
| Al(N | Mg(N | Zn(N | Cu(N | |
| Al | NR | NR | NR | NR |
| Mg | Few bubbles | NR | NR | Solution color change from blue to green, metal oxidized |
| Zn | NR | NR | NR | Solution color change from blue to green, bubbles, magnesium broke down |
| Cu | NR | NR | NR | NR |
Conclusion
In this lab, the researchers found that magnesium is the most active metal and copper and aluminum are the least active metals. The experiment was completed using aluminum nitrate, copper nitrate, zinc nitrate, and magnesium nitrate to see what happened when aluminum, copper, zinc, and magnesium were placed in each solution.
The researchers predicted that zinc nitrate would react with magnesium and aluminium; aluminium nitrate would react with magnesium; copper nitrate would react with zinc, magnesium, and aluminium; and magnesium nitrate would react with none of the metals. This experiment confirmed the researcher’s hypotheses that a reaction would occur between copper nitrate and zinc, and copper nitrate and magnesium; between aluminium nitrate and magnesium; and that no reactions would take place between magnesium nitrate and any of the metals.
This experiment contradicted the researcher’s hypotheses that a reaction would occur between zinc nitrate and magnesium, and zinc nitrate and aluminum; and that copper nitrate would react with aluminum.
In a single replacement reaction, the lone metal is more active than the metal in the compound. The activity series is a list of metals in order from most active to least active from top to bottom; therefore, for a single replacement reaction to occur, the lone metal should be higher in the activity series than the metal in the compound for a reaction to take place.
The group found that aluminum and copper were not reactive at all with any of the solutions. Zinc was somewhat reactive, reacting with one solution. Magnesium was the most reactive metal, reacting with two solutions.
It is possible that while using the pipettes, the same exact amount of solution was not placed in each well as planned. It is also possible that a color change occurred upon the metals in the solutions that some researchers noticed that others did not. A real-life example of a single replacement reaction is the Statue of Liberty.
The outside of the Statue of Liberty is made of copper, the inside made of steel; when the copper oxidized (forming the bluish-green color), a single replacement reaction occurred causing the iron to convert the copper back to copper metal. The iron in the steel rusted.
