As you have known, reactivity of Group I and II metals increases down the group. On the other hand, reactivity of Halogens increases up the group.
What about transition metals? They follow the reactivity series of metals, as shown below:
K | Potassium |
Na | Sodium |
Ca | Calcium |
Mg | Magnesium |
Al | Aluminium |
C | Carbon |
Zn | Zinc |
Fe | Iron |
Sn | Tin |
Pb | Lead |
H | Hydrogen |
Cu | Copper |
Hg | Mercury |
Ag | Silver |
Au | Gold |
Pt | Platinum |
Haha carbon and hydrogen are not metals but are important as there reactivity affects the extraction of different metals!
A (lousy) mnemonic is: Please don’t SCam Me or I call Atticus to Come Zap you. I Threw your Love into Hell!* haha Come avenge Me in SinGaPore!
You were troubled from the first glance at this, but it’s now easy, isn’t it? Go!
*No; I did not throw it into trash, but neither would I catch a grenade or jump in front a train for you.
In theory, a more reactive substance can displace another substance: for instance:
Case 1: Copper and Iron
Dip a copper strip into a solution of Iron (II) Sulphate: Nothing Happens!!!! Not that the entire world went wrong but copper is less reactive than iron, hence no displacement occurred.
Case 2: Copper and Iron (Again…)
Dip an iron strip into a solution of Copper (II) Sulphate. Hey! The colour changes from blue to pale blue and then to green :D….also, you may see copper metal deposit on the surface of the iron strip. This is because the iron atoms displaces the Copper ions from the solution. Originally its Copper (II) Sulphate, now its Iron (II) Sulphate. (The colour changes from bluw to green because copper ions dissolved in water are blue, iron 2+ ions are green.)
The chemical equation is:
Fe (s) + CuSO4 (aq) àFeSO4 (aq) + Cu (s)
Hence solid copper is seen depositing themselves on the surface.
More specifically, this is a electron transfer, or redox reaction. (Redox = Reduction and Oxidation)
Fe (s) + Cu2+ (aq) àFe2+ (aq) + Cu (s)
The same goes for halogen displacement:
Case 3: Iodine Production
To produce iodine, aqueous chlorine is dripped into a solution of potassium iodide. Chlorine reacts with the potassium iodide and displaces iodide ions. The products are potassium chloride and iodine.
KI (aq) + Cl2 (aq) àI2 (aq) + KCl (aq)
Redox equation:
Cl2 (aq) + 2I- (aq) àI2 (aq) + 2Cl- (aq)
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