Unit 5 Flashcards
Ionic Bonding
Ionic Bond
A type of chemical bond that is formed due to the electrostatic attraction between two oppositely charged ions. Generally formed between a Metal and Nonmetal (since Metals are usually Cations and Nonmetals are usually Anions.)
Monatomic Ion
an ion, regardless of its charge, that is the result of a single atom.
Ex. Na+, Ca2+, Al3+, F-, O2-, N3-
Polyatomic Ion
an ion, regardless of its charge, that is the result of multiple atoms that have covalently bonded together. They are USUALLY negatively charged (considered anions) and will often bond with a metal cation.
Ex. NH4+, H3O+, NO3-, CO32-, PO43-, CH3COO-
Form a crystalline structure
Many sizes of ions would stack differently like different sized balls (since the size of the atom (now ion) will change when losing/gaining Valence Electrons) fitting into a box (or forming a cube since we are talking about multiple dimensions.)
High Melting Points
All ions are in contact (bonding) with several others. (think of a slightly positive particle being surrounded by slightly negative particles; it will be attracted to all negative. Also, vice versa…) To overcome these multiple attractions, much energy (heat) is needed.
Strong attractive forces between ions in 3-Dimensions
The attractive forces between oppositely charged objects can be very high (consider Coulomb’s Law.) Combined with the fact of these having several bonds per ion makes it have strong attractive forces.
Hard and Brittle Solids
Since all of the bonds are strong and rigid, any applied force will have effects across many bonds/layers resulting in brittleness. (When a positive “shifts” and makes contact with another positive, the similarly charged particles will repel from each other. This works the same way with the negative and another negative.)
Range of Dissolving Rate in water
Water [as well as Ionic Compounds] is considered polar (has partial ‘+’ and partial ‘-’ regions in the molecule). These charged regions attract oppositely charged atoms. Water can get a strong attraction to the ions (substance is soluble), but the ions may have a stronger attraction to each other (substance is insoluble). (Think of table salt… The Oxygen in water has a higher electronegativity compared to the Chlorine in table salt. So, Oxygen is strong enough to separate the Na+ from the Cl-, resulting in a dissolved substance.)
Large energy release when attractive forces are overcome
Forming Ionic Structures (crystal lattices) takes energy. So, the opposite would be true for the reverse. (If it takes a lot of energy to form, it takes a lot of energy to break/separate. If it takes little energy to form, it takes little energy to break/separate)
Electrically conductive in molten or dissolved form only
To be conductive, charges need to be free to move. Ions are charged (either + or -), but not free to move in a crystal (since here, they would be considered ‘stuck in place’.) Break down the crystal and charges can move. More ions in solution means more conductive with a higher value, since more ions are present and floating around freely. (Think of the water as like a road. Then think of the ions as like a car.)
IUPAC
International Union of Pure and Applied Chemistry
Binary Compound
a compound that contains two elements.
Ternary Compound
a compound that contains three elements.
Unit Cell
a repeating unit that is formed by the vectors spanning the points of the lattice. The most basic unit of a crystal lattice.
Lattice Energy
the amount of energy released when a mole of solid ionic compounds convert into its gaseous ions (in kilojoules per mole or kJ/mol)
