Sourabh Das 17/04/2023

Reactivity Series Experiment

Pre-Lab Answers:

1. When a gas is formed in a reaction, it releases bubbles. In a more vigorous reaction, more bubbles are formed and are released more rapidly. Sometimes the test tube may heat up in a more vigorous reaction.

2. The reactivity of metals are affected by the number of shells that the metal has and the number of electrons in its outer shell.

3. Always wear safety goggles, gloves and a lab coat. Have a tap with running water nearby.

Question:

What is the order of reactivity of copper, iron, magnesium, and zinc with acid?

Hypothesis:

The order of reactivity of the 4 metals from the most reactive to the least is magnesium, zinc, iron and copper.

Materials:

1 MSDS for HCl

4 Pieces of metal (one each of magnesium, zinc, iron and copper)

Dilute hydrochloric acid

1 Grease Marker

4 Test tubes

1 Test tube rack

Safety equipment

1 Pair of tongs

1 Emery cloth or sandpaper

Sourabh Das 17/04/2023

Procedure:

Observations:

Metals Observable ReactionsMagnesium Rapid release of bubbles; completely reacted in 12 minutes; test tube heated up

Zinc Surface covered with bubbles, some bubbles released; no obvious change in temperatureIron Very few bubbles on surface of metal; no bubbles released or temperature change

Copper No visible reaction

Post-Lab Answers:

1. We used mainly 2 criteria to determine the rate of reaction: The change in temperature of the test tube, and the amount of bubbles being released from and covering the surface of the metal.

2. Magnesium had the fastest reaction. Zinc was the next fastest. Iron had a very slow reaction and copper was completely inert.

3. The activity series shows the order in which each metal will react, or how reactive the metal is.

Magnesium Copper Iron Zinc

HCl

Sourabh Das 17/04/2023

Conclusion:

After leaving each metal for 20 minutes, only magnesium had completely reacted. Zinc had bubbles coating its surface with some bubbles rising to the surface of the HCl acid. Iron and copper had hardly reacted.

In terms of the positions of the metals in the periodic table and their electron configuration, magnesium should be the most reactive as it is in the leftmost group of the 4, even though it is in the previous period and has 1 less shell then the other 3 metals. This result is supported by the outcome of the experiment. The other 3 metals are all in period IV so their reactivity in terms of their group number should be: Iron, copper then zinc. Iron and copper follow the trend; however zinc does not in this experiment. This is almost certainly not an experimental error, as there are no obvious flaws to the fairness of the test and zinc was considerably more visibly reactive then copper and iron.

A possible explanation to why this is the case could be that the electron configuration of transition elements vary and many metals having multiple valences due to incomplete inner shells. This may affect the degree to which electron shielding affects the electrons in the outer shell and thus affect the reactivity of the metal.