2.2.2 - Bonding and Structure Flashcards
What does ionic bonding happen between?
A metal and a non metal.
Which way are electrons transferred?
From the metal atom to the non-metal atom.
What holds ionic compounds together?
Oppositely charged ions are formed, which are bonded together by strong electrostatic attraction.
In giant ionic lattices what is each ion surrounded by?
Oppositely charged ions.
How is a three dimensional giant ionic lattice formed?
Ions attract each other from all directions.
Can ionic compounds conduct electricity when solid?
No
Why can ionic compounds conduct electricity when in liquid state?
The ions are free to move around and conduct electricity.
What is ionic bonding?
electrostaic atracion between positive and negatively charged ions.
Why don’t ionic compounds conduct when solid?
Ions are in fixed position and cannot move to carry a charge.
Why can ionic compounds conduct when molten or in solution?
Ions are mobile and are therefore able to carry a charge.
Why do ionic compounds have high melting and boiling points?
Due to the strong electrostatic force of attraction between positively and negatively charged ions.
Why does MgO have require more energy to break down than NaCl?
Mg2+ and O2- bonds are stronger than Na- and Cl- bonds.
What do ionic lattices dissolve in?
Polar solvents, such as water.
What do polar bonds occur between?
Atoms that do not share electrons equally between them.
What is the result of a polar bond?
Results in the atom having very small charges on them.
What do polar water molecules do?
Attract the charged ions in the giant ionic lattice.
What is covalent bonding?
The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms.
What is a dative covalent bond?
A covalent bond in which the shared pair of electrons has been provided by one of the bonding atoms only.
What is an example of a substance which contains a dative covalent bond?
Ammonium ion. NH4+
What does the average bond enthalpy measure?
The energy required to break a covalent bond.
What does a greater average bond enthalpy mean?
The stronger the bond is, therefore more energy is required tot break it.
In shapes of molecules what angles are the biggest?
Lone pair lone pair angles
In shapes of molecules what angles are the smallest?
Bond pair - bond pair angles.
According to electron pair repulsion theory what happens to the bond angle when a lone pair is added?
The distances decreases by 2.5 degrees as the lone pair repels the bond pair.
In a linear molecule what is the bond angle?
180
If there are three bond pairs and no lone pairs what shape the molecule and what is its bond angle?
Trigonal planar and 120
What is the shape of a molecule and bond angle which has four bond pairs and no lone pairs?
Tetrahedral 109.5
What is the shape and bond angle of a molecule which has 3 bond pairs and 1 lone pair
Trigonal pyramidal 107