Unit 1.5 - Solid Structures Flashcards
What are ionic solids made up of?
Oppositely charged ions packed around each other
What’s made up of oppositely charged ions packed around each other?
Ionic solids
What does oppositely charged ions being packed around each other in an ionic solid do?
Maximises the electrostatic attraction between oppositely charged ions
Minimises repulsion between ions with the same charge
Ensuring maximum bond energy
How is maximum bond energy ensured in an ionic solid?
Through the oppositely charge ions being packed around each other, which…
Maximises electrostatic attraction between oppositely charged ions
Minimises repulsion between ions with the same charge
How many Na+ cations surround each Cl- anions and vice versa in sodium chloride?
6
Which salt has 6 cations surrounding the anions and vice versa?
Sodium chloride
Crystal coordination number of sodium chloride
6:6
Which salt has a crystal coordination number of 6:6?
Sodium chloride
Crystal coordination number
The number of anions around each cation in an ionic lattice and vice versa
The number of anions around each cation in an ionic lattice and vice versa
Crystal coordination number
What’s the Crystal coordination of sodium in sodium chloride?
6
How many Cl- anions surround each Cs+ cation and vice versa in caesium chloride?
8
Crystal coordination number of caesium chloride
8:8
Which sal has a crystal coordination number of 8:8?
Caesium chloride
Why do sodium chloride and caesium chloride have different crystal coordination numbers?
Cs+ cation is larger than that of Na+
=more room to accommodate a greater number of anions
Does Cs+ or Na+ have more room to accommodate a greater number of anions? Why? Why is this relevant?
Cs+ as it’s larger, therefore it has a higher crystal coordination number
Is Cs+ or Na+ a bigger cation and what does this mean?
Cs+ is larger, so it has more room to accommodate a greater number of anions, so it has a larger crystal coordination number
Crystal
Atoms or molecules joined together in a repeating pattern to create a certain shape
Atoms or molecules joined together in a repeating pattern to create a certain shape
Crystal
What are the properties of ionic compounds determined by?
The strength of the electrostatic forces between the ions
What do the strength of the electrostatic forces between ions determine?
The properties of ionic compounds
Properties of ionic compounds
High melting and boiling points
Electrical insulators as solids
Electrical conductors when molten or dissolved in water
Brittle
Soluble in water (some)
What type of compounds have the following properties?
High melting and boiling points
Electrical insulators as solids
Electrical conductors when molten or dissolved in water
Brittle
Soluble in water
Ionic compounds
Why do ionic compounds have high melting and boiling points?
Due to the strong electrostatic attraction between the oppositely charged ions which require a lot of energy to overcome
What do the strong electrostatic attraction between the oppositely charged ions which require a lot of energy to overcome cause ionic compounds to have?
High melting and boiling points
Why are ionic compounds electrical insulators as solids?
Ions are in fixed positions and can’t move
What do ions being in fixed positions when solid cause ionic compounds to be?
Electrical insulators as solids
When are ions in a fixed condition in ionic compounds?
As solids
Why are ionic compounds electrical conductors when molten or dissolved in water?
Ions are free to move and carry a charge when voltage is applied
What do ionic being free to move and carry a charge when molten or dissolved in water in an ionic compound cause it to be?
Electrical conductor
When can ions carry a charge to be an electrical conductor when molten?
When voltage is applied
When are ionic compounds electrical conductors?
When molten or dissolved in water
When are ionic compounds electrical insulators?
As solids
What are ionic compounds as solids?
Electrical insulators
What are ionic compounds when molten or dissolved in water?
Electrical conductors
Why are ionic compounds brittle?
Due to repulsion between like charged ions when the layers of ions are shifted by a large enough force
What is caused by repulsion between like charged ions when the layers of ions are shifted by a large enough force in an ionic compound?
They’re brittle
Why are certain ionic compounds soluble in water?
When the solid dissolves, the ions are surrounded by water molecules, which are attracted to the ions due to the water molecules having a permanent dipole
Why are water molecules attracted to (some) ions?
Due to water molecules having a permanent dipole
What does the fact that water molecules have a permanent dipole cause with ions and what does this lead to?
When an ionic solid is dissolved, the ions are surrounded by water molecules, which are attracted to the ions due to the water molecules having a permanent dipole - solubility in water
Which ionic compounds are soluble in water?
All group I compounds
All nitrate compounds
Most halide compounds
What’s special about the following ionic compounds?
All group I compounds
All nitrate compounds
Most halide compounds
Soluble in water
What are giant covalent structures made up of?
Atoms that form multiple covalent bonds to other atoms forming a giant lattice structure
What are formed of atoms that form multiple covalent bonds to other atoms forming a giant lattice structure?
Giant covalent structures
Lattice
Consistently repeating pattern of atoms
Consistently repeating pattern of atoms
Lattice
Give 2 examples of giant covalent structures?
Diamond and graphite
What are diamond and graphite examples of?
Giant covalent structures
What are diamond and graphite forms of?
Elemental carbon
Name two forms of elemental carbon
Diamond and graphite
What are diamond and graphite to carbons?
Allotropes
Name two allotropes of carbon
Diamond and graphite
Allotrope
Different structures of the same element
Different structures of the same element
Allotropes
How many carbon atoms does each carbon atom bond to in diamond?
4
What bonds with 4 others similar to it in diamond and graphite?
Carbon atoms
Which allotrope of carbon forms 4 strong bonds to other carbon atoms?
Diamond
What type of structure does diamond have?
Tetrahedral arrangement, forming a giant 3D structure
Which allotrope of carbon has a Tetrahedral arrangement, forming a giant 3D structure?
Diamond
How many covalent bonds can carbon form?
4
How many bonds are made by each carbon atom in graphite?
3
Which allotrope of carbon forms 3 bonds with other carbon atoms?
Graphite
Describe the structure of graphite
Hexagonal layers (only 1 layer thick), which are held together by weak Van der Waal forces
Which allotrope of carbon has hexagonal layers which are only 1 layer thick?
Graphite
What are the hexagonal layers of graphite held together by?
Weak Van der Waals forces
What are the properties of giant covalent structures determined by?
The strength of the covalent bonds between the atoms
What is determined by the strength of the covalent bonds between the atoms?
The properties of giant covalent substances
What are the properties of both diamond and graphite?
High melting and boiling points
Insoluble
What are the following properties for?
High melting and boiling points
Insoluble
Both diamond and graphite
Why do both diamond and graphite have high melting and boiling points?
Each carbon atom has 3 or 4 strong covalent bonds, which require a lot of heat energy to overcome