A: Title and Date:

The Reactions of 5 different metals with hydrochloric acid
Thursday 10th December 2009


B: Aim:

To observe the reactivity between 5 metals (Al, Cu, Mg, Zn, Fe) and hydrochloric acid, and to rank them according to the reaction's intensity

C: Variables:


The Variable Table
Independent

Different Kinds of Metals in Powder form



Aluminium (Al), Copper (Cu),
Magnesium (Mg), Zinc (Zn), Iron (Fe)

Dependent

Reaction/Time



Limit the time (2 minutes)
and observe the reaction.

Constant

Hydrochloric Acid


10ml


Amount of the Metals


One Spoon of the metals (powder form, approximately 1g)


D: Hypothesis:

If we change the metal we put in, then the reaction of them will get violent if the element is further away from full valence shell, or if they have too many valence shell, because both of them make the element unstable.

E: Equipment and Materials

· Hydrochloric Acid (HCl), 50 ml
· Approximately 1 gram of each metal.
· A stop watch
· 5 Test Tubes
· Test Tube Rack
· A Pipette
· A Spoon

F: Method:


1. Gather all your material
2. Pour Hydrochloric acid 10ml in to the test tube
3. Then put some chunks of metal in to the test tube with the hydrochloric acid, and you have to do one at a time.
4. Start the stop watch at the same time when put the metal in to the test tubes
5. Observe what happens and record down the observations for 2 minutes
6.Repeat number 2 to number 6.


G: Diagram of Apparatus

H: Observations:


The Reaction of 5 metals and Hydrochloric Acid

What Happened in 2 minutes
After 2 or 3 days
Zinc

Some bubbles came up slowly.

Bubbles on the zinc

The Zinc got smaller.

Both sides turned white and they are peeling off by it.
Magnesium

Bubbles quickly and steam came out.

Strong reaction, and the Magnesium turned white.

We can also hear sounds, and heat was coming out.

Everything disappeared.

The acid became clearer.

There are only a little bit of magnesium left.
Copper

Changes the colour.

It bubbles a bit, and it also stick to the side of the test tube.

Little piecie break and floating on top, also some parts broke from the copper and then was stuck at the bottom.

There are some holes in the copper but it didn’t go through.

The colour changed to white.

The copper became rusty.
Iron

It was bubbling and some parts of the iron are floating on top of the acid

There is a huge bubble stuck on the iron and more bubbles are floating up and down.

The liquid is transparent.

The acid’s colour turned into yellow and the iron powder rusted

Aluminum

It doesn’t sink when it meets the acid.

It gets a bit wet, but it doesn’t melt at all.

The acid and the powders were separated completely.

Most Reactive Metals:
Based on the observations we had came up with which metal react better to the acid:
1. Magnesium
2. Zinc
3. Iron
4. Copper
5. Aluminium

J: Conclusion:

1.

The most reactive metal was Magnesium, then Zinc, Iron, Copper, and Aluminium.

2.
The results supported the hypothesis that the element will be most reactive when it is unstable, because of the reasons such as not many electrons in the last valance shell or holding up too many valence shells. For example, Magnesium had only 2 electrons in the last valence shell while other had more.

3.

The greater the ease with which an element loses its electrons and acquires a positive charge, the greater is its reactivity. Further, the greater the number of shells and lesser the number of valence electrons, the greater is the reactivity of the metal.(Author Unknown) Given this fact, we could know that the more stable the element is (when an element has more electron in its last valence shell), the less reactive the element is. Since it takes more energy to take more electrons than less number of electrons, the reaction will be softer. Also, when an element has more number of valence shell while it has less number of electrons in the last valence shell, the reaction will be even more violent, since the nucleus cannot hold the electrons further away, meaning electrons are almost free, reaction will happen easier.

K: Evalutation1.
The result was not that reliable because we haven't repeated the experiment again to check, and since we didn't measure the amount of metal we put in.

2.
The method was easy to follow, and you can do exactly what the method tells you. The method tells us not to do all the experiment at the same time because if we do then we won’t be able to record the observation correctly and detailed.

3.
Weakness
Improvements
We didn’t measure
the amount of metals we use

Measure the amount of metals
we will use.

We used both powder and a solid type;
we used solid for copper

Use same form of the metal.
4.
This was a fair test because we had clearly set out method. Also, we measured the amount of hydrochloric acid each time we put in. We used different spoon to put metals in each time in order to prevent putting small portion of other metals in the acid. Another thing that made this a fair test was that we had a stop watch to measure time correctly.