Ionic and covalent bonding Flashcards
covalent substances are made up of…
non-metallic elements only
What are the 5 main groups all substances can be grouped into?
- metals
- ionic compounds
- simple molecular substances [covalent substances]
- giant covalent substances [covalent substances]
- macromolecules [covalent substances]
Ionic compounds are made up of?
metallic and non-metallic elements
what are macromolecules?
Very large molecules such as polymers made up by joining of many small molecules by covalent bonds
What are the giant covalent substances?
- Silicon dioxide (SiO2)
- Graphite (just carbon)
- Diamonds (just carbon)
WHAT TYpe if ions can be found in ionic compunds?
Cations and anions
What is the structure of ionic compounds?
Giant ionic lattice structure
What is the attractions present in an giant ionic lattice structure?
Strong electrostatic FOA between the oppositely charged ions that are held in fixed position within the lattice structure
What are properties of ionic compounds?
- high MP
- high BP
- conduct electricty in molten and aq state but NOT solid state
- soluble in water, insoluble in organic solvents
- hard but brittle
define ionic bond
Mutual electrostatic attraction between ions of opposite charges
How to explain why ionic compounds have high MP and BP
Structure - Ionic compounds have giant ionic lattice structure
Attraction - strong electrostatic FOA between opp charged ions
Energy - large amt of energy is needed to overcome the strong electrostatic FOA
Conclusion - Thus, ionic compounds have high BP and MP
How is it that electricity conducted in ionic compounds in molten state but not solid state?
In solid state, the strong electrostatic FOA holds the ions tgt in fixed position and since ions cannot act as mobile charge carriers, they cannot conduct electricty at Solid state.
However in molten state the electrostatic FOA is weakened due to heat energy causing them to become liquid state and thus the ions are no longer held in fixed positions.
Thus ionic compunds are mobile charge carriers in molten state but not solid state.
What is the forces in covalent bond?
- covalent bond between atoms (eg Cl2)
- intermolecular forces between molecules
why doe simple molecular substances have low MP and BP?
- they have a simple molecular structure with
- weak intermolecular forces present between molecules
- Little amt of energy needed to overcome these weak forces of attraction
- Thus the low MP and BP
Define volatile
easily evaporates at normal temp