Unit 4. Ionic Bonding Flashcards
Simply explained what is ionic bonding
Ionic bonding involves the transfer of one or more electrons from the outer shell of one atom to the outer shell of another atom
What are cations
Cations are atoms with a positive charge
What are anions
Anions are atoms with a negative charge
What are anions and cations
Ions
What is an ionic bond?
The electrostatic attraction between oppositely charged ions. They are formed by elements with an electro negativity difference greater than 1.8
What are ionic compounds composed of?
A metal and non-metal
What are the exceptions to what ionic bonds are usually composed of (non metal and metal)?
Salt ammonium chloride (NH4Cl), it features ionic bonding between the ions and covalent bonding between the atoms that up the ammonium ion.
How are ions arranged in an ionic compound?
Regular crystalline structure, a lattice structure
How many chloride ions surround a sodium ion in salt, a lattice structure and vise versa
What is the ratio of sodium ions to chloride ions in salt based on the molecular formula NaCl
Each sodium ion is surrounded by 6 chloride ions
And vise versa
1 to 1
What is ionic bonding described as
Non directional, as the force of attraction occurs in all directions around the indictable ions.
What is the coordination number of sodium ions and chloride ions in salt
6, as both ions are in contact with 6 other ions
What are the general patterns for certain groups for their formation of ions
Group 1: 1+ charge
Group 2: 2+ charge
Group 13: 3+
Group 15: 3-
Group 16: 2-
Group 17: 1-
Group 18: do not form ions
List formulae of positive ions
Lithium, Li+
Sodium, Na+
Potassium, k+
Caaesium, Cs+
Calcium, ca 2+
Magnesium Mg2+
Aluminium Al 3+
Zinc Zn 2+
Copper (II) Cu2+
Lead Pb 2+
Iron (II) Fe2+
Iron (III) Fe3+
List formulae of negative ions
F-
Cl-
Br-
I-
Oxide O2-
Sulfide S2-
Nitride N3-
Phosphide P3-
What are polyatomic ions
Polyatomic ions are ions that consist of more than one atom. The atoms that make up the polyatomic ion are bonded by covalent bonds, but the type of bonding that occurs between a polyatomic ion and another ion is ionic.
Give the formulae of polyatomic ions
Name Formula
Hydroxide OH−
Nitrate NO3−
Nitrite NO2−
Hydrogen carbonate HCO3−
Carbonate CO32−
Sulfate SO42−
Sulfite SO32−
Phosphate PO43−
Chlorate ClO3−
Perchlorate ClO4−
Chlorite ClO2−
Hypochlorite ClO−
Ammonium NH4+
Are ionic compounds neutral
Yes the oppositely charged ions must cancel out to form a neutral compound
What is the formula of an ionic compound
The formula of an ionic compound is simply the ratio of the ions that make up the compound, so that, overall, the charges cancel out.
Melting and boilings points of ionic compounds
The strong attraction between the ions results in ionic compounds having relatively high melting and boiling points. This means that relatively large amounts of energy are required to break these forces of attraction between the ions. For this reason, ionic compounds are solids under standard conditions.
What does the melting point of an ionic compound depend on
the ionic charge and the ionic radius of its component ions. The greater the charge on the ion and the smaller its ionic radius, the greater the attraction between the oppositely charged ions and the higher the melting point.
What is volatility
a term used to describe how easily a substance evaporates
Volatility of ionic compounds?
Ionic compounds have very low volatility because of the strong forces of attraction between the ions in the lattice structure.
Solubility of ions?
Most ions are soluble. The solubility of an ionic compound depends somewhat on the forces of attraction between the water molecules and the ions in the lattice structure.
How do ionic compounds dissolve in water
The first step in the dissolving process is the break down of the lattice structure. The second step involves the separated ions being surrounded by water molecules, which is known as hydration (Figure 1). When this happens, the solid dissolves
