Aim: To find the reactivity of aluminum, copper, magnesium, and zinc in hydrochloric acid and rank them on a scale of reactivity from most to least.
Variables:



What is/are
the
Variable?

How will it be changed?
How will it be measured?
How will it be controlled?

Independent Variable
Metal dissolved in hydrochloric acid
Use different metals in each experiment.
Dependent Variable
Time taken for each metal to dissolve in to hydrochloric acid
Use a stop watch to time the amount of time taken to dissolve.
Controlled variables / Constants
Amount of Hydrochloric acid
Measure the amount of Hydrochloric acid and use that amount in each experiment
Container used
Use a test tube in each experiment
Amount of metal used
Measure the metal shavings and make sure it’s the same for each experiment
The timer
Same person holds the stop watch
Hypothesis: If a metal is closer to having a complete shell, then it will be react faster because there are fewer electrons to lose or gain.


Equipment and Materials:

· 5 test-tubes
· ¼ mm of iron, aluminum, copper, magnesium, zinc powder
· Stop watch
· 5 ml of Hydrochloric acid in each test tube
· Lab coat
· Safety goggles

Method:

1. Gather all materials
2. Place ½ cm of each metal powder in each test tube
3. Pour the 5ml of acid in one of the test tubes (were lab coat and safety googles)
4. Time how long it takes for it to dissolve (maximum 6 mins)
5. Record what you see at 1 min intervals
6. Repeat steps 3-5 until all metals have been tested.


Reactions of different metals in hydrochloric acid in a six minute time froame :
Element/Time in acid
1 Min
2 Min
3 Min
4 Min
5 Min
6 Min
Iron
Large bubble formed and little bubbles formed
Larger bubbles are coming from the iron and the acid is a bit foggy
Small streem of bubbles are coming from the middle of the iron
Larger bubble streams have formed near the edge and the mass seems to have decreased
Acid has become very foggy and large bubbles are coming from every were
On final time the acid has become semi opaque and the mass seems to have decreased greatly. Note: when acid was pored out horrible smell came from test tube
Aluminum
Instantly reacted with acid and formed an odd layer of aluminum that prevents air from escaping.
Large air bubble formed under the crust and is stuck.
Some of the aluminum powder has fallen down from the crust.
Powder continues to fall and is making the acid opaque
Powder has stopped falling fromm the crust and has settled at the bottom of the test tube
Final time: Everything has separated, the powder has fallen to the bottom, acid is in between the crust and powder, and the crust has stayed at the top.
Copper
No reaction (N/R)
N/R
N/R
N/R
N/R
N/R
Magnesium
Reacted immediately to the acid and began to bubble and condensation formed near the top. Steam was coming out
At two minuts the reaction settle down but there are still bubble coming from the magnesium.
The acid is opaque and there are bubbles suspended in the acid. The magnesium at times “jumps.
The water is more opaque and more there are more bubbles suspended and more bubbles come from the magnesium.
The bubbles have made the water more opaque than the white reaction. Large bubbles are coming from the bottom of the magnesium.
The acid is very bubbled and more are coming from the magnesium. The magnesium is warm.
Zinc
Instantly reacted and bubbled into a grey crust similar to aluminum and also separated. Begins to bubble
Has become suspended and a large amount of bubbles come from the bottom. Crust is being suspended by the bubbles.
Crust has become enlarged and looks like its reaching down. The bottom is reaching up to the crust.
The separation has become very small and the crust is falling down.
It’s a bit war. There is no powder left and it seems to be inflated by the air coming from the bottom.
Bubble is stuvk in the crust crust has collapsed over the air bubble and is suspended in between the semimetal zinc and the zinc crust.

PICTURES FROM OBSERVATIONS- SENT TO MR OTTO :)

Conclusion:
From this experiment, we found out the reactivity of aluminum, copper, magnesium, and zinc in hydrochloric acid and ranked them on a scale from most reactive to least reactive- magnesium, aluminum, zinc, iron, copper.
Magnesium:
Symbol: Mg
Atomic number: 12
2 away
Aluminium:
Symbol: Al
Atomic number: 13
3 away
Zinc:
Symbol: Zn
Atomic number: 30
6 away
Iron:
Symbol: Fe
Atomic number: 26
8 away
Copper:
Symbol: Cu
Atomic number: 29
7 away
These results do support our hypothesis because the elements with the lower atomic mass and number reacted faster. The reason that the magnesium was more reactive that the copper was because it was closer to becoming a noble gas so it has to lose less electrons to lose so there is a quicker reaction compared to a metal that has a lot of electrons to lose.

Evaluation:
The data we have collected is pretty reliable as we only had one independent variable in all the experiments. The method we used to collect our data was fairly reliable, but it has its pros and cons.


Weakness
Improvement
It was hard to measure the amount of each sample and make sure they were equal.
We should have drawn a line on the test-tubes to indicate ½ cm using an erasable marker. This would have made it easier and more accurate to measure the amount of each sample.
Each experiment was only done once.
We should have done each experiment at least twice, to have a fairer lab.