Ionic Compounds Flashcards
Formation of Ionic Compounds
Ionic compounds are formed when one or more valence electrons are transferred from a metal atom to a nonmetal atom
Ionic bond – the electrostatic force of attraction between a positive ion and a negative ion
Repeating bonds in Crystal Lattice
Repeating bonds is formula unit. One formula unit is a molecule.
This happens over and over again with trillions and trillions of sodium and chlorine atoms
Melting point of Ionic Compounds
The melting point of a compound is the temperature at which it changes from a solid to a liquid
Ionic compounds have relatively high melting points because their ions are held together by strong electrostatic forces (ionic bonds)
The boiling point is liquid to gas. Requires a lot of energy to remove a particle from the formulaic bond due to the electrostatic force.
Hardness of Ionic compounds
Held together by the attraction of oppositely charged ions (electrostatic forces)
Resistant to being stretched or compressed
If struck with a hammer ions become distorted and repel one another causing the crystal to break or shatter
Brittle is when force is being applied. This causes ions to become distressed, changing heir position in the bond. The similar charges line up and repel each other. This causes the ionic compound to break.
Ionic Compounds Dissolve in Water
When an ionic crystal is placed in water, water molecules surround each ion and separate it from the crystal
NaCl and water example:
O atoms in water are slightly negative, so they attract and surround Na+
H atoms in water are slightly positive, so they attract and surround Cl-
Not a chemical reaction, the ions just get smaller and smaller. Conductivity is the movement of charge.
Why do dissolved ionic compounds conduct electricity?
When an ionic compound is dissolved in water (ie. it’s aqueous form), the result is an electrolyte
The dissolved ions are able to move freely, and thus to carry electric charges, through the water
