Topic 2 - Bonding and Structure Flashcards
Describe the effect of charge on ionic bond strength
The greater the charges, the greater the ionic bond strength
Describe the effects of ionic radius on bond strength
The smaller the ionic radius the greater the bond strength
How does the electrolysis of a green ionic solution of Cu 2+ ions and CrO4 2- ions provide evidence for the existence of ions?
The Cu 2+ ions will migrate to the cathode, turning the solution there blue, and the CrO4 2- will migrate to the anode, turning the solution there yellow. This implies that the substances present have a charge, and are therefore ions.
Describe the relationship between bond length and bond strength
The stronger the bond, the shorter the bond is.
What shape is Beryllium Dichloride and what angles are present?
Linear
180*
What shape is Boron Trichloride and what angles are present?
Trigonal Planar
120*
What shape is Methane and what angles are present?
Tetrahedral
109.5*
What shape is Phosphorus Pentachloride and what angles are present?
Trigonal Bipyramidal
90* and 120*
What shape is Sulphur Hexachloride and what angles are present?
Octahedral/Hexagonal
90*
What shape is Water and what angles are present?
V-Shaped
104.5*
What shape is Ammonia and what angles are present?
Trigonal Pyramidal
107*
Define electronegativity
The ability of an atom to attract a bonding pair of electrons in a covalent bond to its nucleus.
How does the electronegativity of ions affect an ionic bond’s covalent character?
The greater the difference in electronegativity between the two ions, the lesser the degree of covalent character.
How does the charge density of ions affect an ionic bond’s covalent character?
The greater the charge density of the cation, and the smaller the charge density of the anion, the greater the covalent character.
What are London Forces?
Temporary attractive forces that result when the electrons in a molecule occupy positions that makes a temporary dipole, which itself induces dipoles in adjacent molecules. The opposing dipoles then cause attraction between the molecules.
Describe and explain the relationship between the boiling points and relative atomic masses of alkanes
The greater the Mr, the greater the boiling point. This is because the only significant intermolecular interaction in alkanes is the London Force, which increases in significance with the mass, as there are more atoms to interact.
Describe and explain the relationship between the boiling points and relative atomic masses of alcohols
The greater the Mr, the greater the boiling point. The trend starts much higher than that of alkanes. This is because, in addition to London Forces, there is also one hydrogen bond possible per molecule with the OH group.
Describe and explain the relationship between boiling point and number of period of halide of hydrogen halides.
The trend excluding hydrogen fluoride is the greater the period number, the greater the boiling point. HF is an exception as it has hydrogen bonding in addition to London forces, which have a consistent increasing trend.
What are the criteria for an effective solvent?
The solute-solvent intermolecular attractions must be stronger than the solvent-solvent and solute-solute intermolecular attractions.
What are the bonding and structure of A, B, C and D?
MT EC(s) EC(l) Soluble in water
A 1083 good good no
B 119 poor poor no
C 2230 poor poor no
D 801 poor good yes
A - Metallic bonding and giant structure
B - Covalent bonding and discrete/simple structure
C - Covalent bonding and giant structure
D - Ionic bonding and giant structure
