SS1: CHEMISTRY - 1ST TERM
Introduction to Chemistry and Laboratory Apparatus | Week 15Topics|1 Quiz
Nature of Matter | Week 23Topics|1 Quiz
Separation Techniques I | Week 31Topic|1 Quiz
Separation Techniques II | Week 45Topics|1 Quiz
Particulate Nature of Matter I | Week 55Topics|1 Quiz
Particulate Nature of Matter II | Week 69Topics|1 Quiz
Symbols, Formulae & Oxidation Number | Week 77Topics|1 Quiz
Laws of Chemical Combination | Week 84Topics|1 Quiz
Chemical Equation & Chemical Combination (Chemical Bonding) I | Week 94Topics|1 Quiz
Chemical Combination (Chemical Bonding) II | Week 104Topics|1 Quiz
Chemical Combination (Chemical Bonding) III & Shapes of Covalent Molecules | Week 113Topics|1 Quiz
Co-ordinate Covalent or Dative Bonding
In co-ordinate covalent bonding, electrons are still shared but it is only one of the participating atoms that donate the pair of electrons to be shared. Such a pair of electrons is called the Lone pair.
Co-ordinate covalent bonding occurs between an atom that has a Lone-pair (unshared pair) of electrons in the outer shell and another atom that has an empty valence orbital and requires one pair of electrons to complete an octet or duplet structure.
The atom that contributes the pair of electrons to be shared is known as donor-atom, while the other is the acceptor atom.
Formation of Ammonium ion (NH4+)
Ammonia and water molecule possess Lone pair and they can enter into a co-ordinate covalent bonding. When Ammonia (NH3) reacts with Hydrochloric Acid (HCl) the H+ from HCl accepts a Lone pair of electrons from Ammonia (NH3) to form a co-ordinate covalent bond. The H+ will attain a stable duplet structure of helium while the Nitrogen atom of the ammonia will also be stable.
Formation of Hydroxonium Ion or Oxonium Ion (H2O+)
Examples of Compounds that Exhibit Co-ordinate Covalent Bond:
NH3Cl – Ammonium Chloride or
NH4+ – Ammonium ion
H3O+ – Hydroxonium ion or oxonium ion
[CU(NH3)4]2+ – Tetrammine copper (II) ion
[Ag(NH3)2]– – Silver diammine ion
Properties of Co-ordinate Covalent Compounds
Covalent and co-ordinate covalent compounds have similar properties but co-ordinate covalent compounds are less volatile than covalent compounds
1. (a) State four differences between Electrovalent and Covalent Compounds
(b) State the type of bonding formed in the following
(i) Carbon(IV) Oxide
(ii) Oxonium ion
(iii) Calcium ChlorideView Answer
2. The Electronic configuration for the metal Calcium, the non-metals Silicon, and Chloride can be represented as
Ca – 2, 8, 8, 2
Si – 2, 8,4
Cl – 2, 8,7
Explain in terms of electrons, the formation of Calcium Chloride and Silicon Chloride.
Give two differences in physical properties you would expect between Calcium Chloride and Silicon ChlorideView Answer
3. (a) Write down the electronic configuration of the Elements Q, R, and S, whose atomic numbers are as follows
(b) Draw the diagrammatic representation of the compound formed between Q and R
(c) What is the Electronic configuration of the ions in the resulting compound between Q and R?
(d) Is Q a metal or non-metal?View Answer
4. (a) (i) What is Dative bonding?
(ii) State one condition that must be met for Dative bonding to take place
(b) Given the following Atomic Numbers X = 12, Y = 17
(i) Write the formula of the Compound formed between X and Y
(ii) Name the type of Bond formed in 4b(i)
(iii) Give a simple definition of the type of Bond formed.View Answer