Form 4 Chapter 4 - Periodic Table of Elements 3

Final part for this chapter:

More about Periods in the Periodic Table:
Reactions:
1) metal oxide + water --> basic solution
2) non-metal oxide + water --> acidic solution
3) oxide + acidic/basic solution will produce different results, as seen below.
- metal oxide + acid --> salt + water
- metal oxide + base --> no reaction
- non-metal oxide + acid --> no reaction
- non-metal oxide + base --> salt + water
- amphoteric + acid --> salt + water
- amphoteric + basic --> salt + water
(An example of an amphoteric substance is aluminium oxide, Al(OH)3.)

Transition metals

Characteristics:
- high b.p & m.p
- high density
- conductors
- shiny
- ductile
- malleable
- can form a coloured solution in a compound
Examples:
Fe 2+ ions - Green
Fe 3+ ions - Brown
Cu 2+ (Copper) ions - Blue
Co 2+ (Cobalt) ions - Pink
CrO4 2+ (Chromate) ions - Yellow

- catalyst in a reaction
Examples:
Note that <--X--> indicates a reversible reaction with transition metal X.
a) N2 + 3H2 <--Fe--> 2NH3 (Found in the Haber Process)
b) Zn + H2SO4 --CuSO4--> ZnSO4 + H2
c) Contact Process
- S + O2 --> SO2
- 2SO2 + O2 <--V2O5--> 2SO3 (Vanadium Pentoxide / Vanadium (V) oxide)
- SO3 + H2SO4 --> H2S2O7
- H2S2O7 + H2O --> 2H2SO4
Note that the Contact Process involves the production of sulphuric acid. (Chapter 9)

- forms complex ions/compounds (KMnO4 - potassium permanganate, K2Cr2O7 - potassium dichromate, K4Fe(CN)6 - potassium hexacyanoferrate(II).)
- compounds of transition metals contains more than one oxidation number
Example: Iron(II) ions, Iron(III) ions, Copper(I) ions, Copper(II) ions.

And that concludes chapter 4.