📚🔥Chemistry 1.5 -Solid Structures Flashcards
What co-ordination does sodium chloride have?
What does this mean?
6:6 co-ordination
-this means that 6 Cl- cations can’t fit around the Na+ anion
(Learn how to draw)
What do-ordination does caesium chloride have?
8:8 co-ordination
-this means that each Cs + anion is surrounded by 6 Cl- cations
(Learn how to draw)
Name some physical properties of the chlorides
- Hard, Brittle solids
- high melting pints (due to the lattice which contains strong ionic vines which require lots of heat energy to break)
- do NOT conduct electricity in a solid state as ions are fixed
- DOES conduct electricity in molten state/solution
- most are insoluble in water
What does crystal chlorides conduct electricity in a solid state?
Because ions are fixed and are not free to move and carry an electrical charge
Why can crystal chlorides conduct electricity in a solution/molten state?
Because the ions are free to move to the oppositely charges electrodes and conduct electricity
Why are most crystal chlorides soluble?
Soluble becaus the polar water molecule orient themselves around the Na+/Cs+ and Cl- ions which hydrates them so water can separate the ions
Why does caesium chloride have a larger co-ordination than sodium chloride?
Because the caesium ion is larger than the sodium ion and therefore 8 Cl- can occupy Cs+ compared with only 6 Cl- around Na+
What structure is diamond?
What arrangement does diamond have (according to VSEPR)?
What bond angle?
- Giant Covalent structure
- Diamond has a tetrahedral arrangement with a bond angle of. 109.5 degrees
Name some physical properties of diamond
- Hard solid
- very High boiling/melting point
- insoluble in water
- does not conduct electricity
Explain why diamond has a high melting/boiling point
Because each carbon atom makes 4 strong covalent bonds (meeting the maximum valency) which take a lot of energy to break
Explain why diamond is insoluble in water
Evacuee it can’t form hydrogen bonds with the water as there is no difference in electronegativity between the carbon atoms
Explain why diamond would be a good insulator
Because there are no delocalised electrons as maximum valency is met and therefore no medium to carry the electrical current through the structure
Name the type of structure that graphite has and the arrangement (according to VSEPR)
Giant covalent structure
-it is a planer hexagonal layered structure
Name the physical properties of graphite
- soft solid
- high melting and boiling point but lower than that of diamond
- insoluble in water
- conducts electricity
- is a lubricant
Explain why graphite has a relatively high melting and boiling point which is still lower than diamonds
Each carbon atom makes 3 strong covalent bonds which require a lot of heat energy to break, however as only 3 bonds need to be broken the mp is lower than diamonds
Explain why graphite conducts electricity
There is a delocalised electron not used up in bonding which can carry electrical charge to conduct electricity
Explain why graphite is a lubricant
The planner hexagonal layered structure has layers which have weak van der Waals forces between them that can be easily broken to allow the layers to slide over one another
Name the physical properties of iodine
-low melting/boiling point
-soft and volatile
-very very very slightly soluble in water
-can’t conduct electricity
-evaporates easily to form a purple vapour
(Black solid-purple vapour; sublime)
Explain why iodine has a low melting/boiling point?
Weak van der Waals forces acting between the I2 molecules which are easily broken by heat
Why is iodine soft and volatile?
Because iodine is only held together by weak van der Waals forces
Why can’t iodine conduct electricity?
Because it has no delocalised electrons free to carry an electrical charge
What can iodine dissolve freely in?
Organic solvents
Name some properties of ice
- unusually High melting/boiling point
- less dense than water so it floats
- does NOT Conduct electricity
Name some properties of metals
- shiny
- hard
- high melting/boiling point
- can conduct electricity/heat
- malleable
- ductile
