Site hosted by Angelfire.com: Build your free website today!

Chemistry Note

subglobal1 link | subglobal1 link | subglobal1 link | subglobal1 link | subglobal1 link | subglobal1 link | subglobal1 link
subglobal2 link | subglobal2 link | subglobal2 link | subglobal2 link | subglobal2 link | subglobal2 link | subglobal2 link
subglobal3 link | subglobal3 link | subglobal3 link | subglobal3 link | subglobal3 link | subglobal3 link | subglobal3 link
subglobal4 link | subglobal4 link | subglobal4 link | subglobal4 link | subglobal4 link | subglobal4 link | subglobal4 link
subglobal5 link | subglobal5 link | subglobal5 link | subglobal5 link | subglobal5 link | subglobal5 link | subglobal5 link
subglobal6 link | subglobal6 link | subglobal6 link | subglobal6 link | subglobal6 link | subglobal6 link | subglobal6 link
subglobal7 link | subglobal7 link | subglobal7 link | subglobal7 link | subglobal7 link | subglobal7 link | subglobal7 link
subglobal8 link | subglobal8 link | subglobal8 link | subglobal8 link | subglobal8 link | subglobal8 link | subglobal8 link

Periodicity

Feature Title

In this chapter you should be able to:

  • Describe the arrangement of elements in the periodic table in order of increasing atomic number
  • Distinguish between the terms group and period
  • Deduce the relationship between the electron configuration of elements and their position in the periodic table
  • Describe and explain the periodic trends in atomic radii,ionic radii,ionization energies,electronegativity and melting points for the alkali metals (Li -> Cs) halogens (F -> I) and period 3 elements Na -> Ar)
  • Discuss the similarities in chemical nature of elements in the same group
  • Discuss the change in nature,from metallic to non-metallic, of the elements across period 3.
  • Explain the physical properties of the chlorides and oxides of the elements in the third period (Na -> Ar) in terms of their bonding and structure
  • Describe the chemical trends for the chlorides and oxides
  • Lis the characteristic properties of transition elements
  • Identify which elements are considered to be typical of the d-block elements
  • Describe the existence of variable oxidation states in d-block elements
  • Define the term 'ligand'
  • Describe how complexes of d-block elements are formed
  • Explain why some complexes of d-block elements are coloured
  • Outline the catalytic behaviour of d-block elements are coloured

 

 

 

Oxides of The 3rd Period

Formula    Na2O      Mg2O      Al2O3      SiO2       P4O10       SO3       Cl2O7

-Sodium oxide,Magnesium oxide and Aluminium oxide are ionics,which results in high melting points and electric conductivity.
-Aluminium oxide is amphoteric.
-Silicon dioxide is macromolecular structure,which high in boiling point.
-At the end of the period,simple molecular structures results in low melting and boiling points
-Oxides of electropositive elements form alkaline solution
    Na2O(s)   +    H2O(l)   à   2NaOH(aq)

-Amphoteric nature of Al2O3 is shown by the reaction with HCl and NaOH
     Al2O3(s)   +    2NaOH(aq)     +    3H2O(l)  à  2NaAl(OH)4(aq)
     Al2O3(s)   +    6HCl(aq)   à   2AlCl3(aq)   +    3H2O(l)

-Silicon dioxide form a weak acid
    SiO2(s)   +    2NaOH(aq) à   Na2SiO3(aq)    +    H2O(aq)

-Phosphorus oxide,sulfur oxide and chlorine oxide are strong acids.
   SO2(g)   +   H2O(l)    à  H2SO3(aq)
   P4O10(s)  +   6H2O(l)   à  4H3PO4(aq)
   Cl2O7(l)   +   H2O(l)   à   2HClO4(aq)
   

 

| Forum | ©2007 Syamil Shakir