Chapter 3.4 - Bonding And Physical Properties Flashcards

1
Q

State the properties of graphite

A
  • Slippery
  • Can conduct electricity
  • High mp
  • Insoluble
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2
Q

Explain why graphite is slippery

A

Weak bonds between the layers in graphite are easily broken, so the layers can slide over each other

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3
Q

Explain why graphite is a good conductor of electricity

A

Graphite has delocalized electrons which carry charge

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4
Q

Explain why graphite has a high mp

A

Because of the strong covalent bonds in the hexagon sheets graphite has a very high mp

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5
Q

Why is graphite insoluble ?

A

The covalent bonds in the sheet are too strong to break

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6
Q

Describe the bonds in diamond

A

Each carbon atom is covalently bonded to four other carbon atoms forming a tetrahedral shape

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7
Q

State the properties of diamond

A
  • high mp
  • hard
  • good thermal conductor
  • can’t conduct electricity
  • insoluble
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8
Q

Explain In terms of its structure and bonding, why nickel conducts electricity

A
  • metallic bond,

- strong attraction between positive ions and delocalized electrons

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9
Q

Explain why CHF3 has a higher mp than CF4 (3)

A

CHF3 contains polar bonds,
There are permanent dipole ,

CF3 contains polar bonds but they cancel each other out due to the shape, there are van daar waals forces between them

Therefore CHF3 has strong intermolecular forces requiring more energy to break dowm

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10
Q

Give the name of the type of crystal structure shown by silicon dioxide

A

Giant covalent structure

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11
Q

Explain why silicon dioxide does not conduct electricity when molten

A

No delocalized electrons

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12
Q

Deduce why the bonding in nitrogen oxide is covalent rather than ionic

A

Small electronegativity difference

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13
Q

Suggest why graphene is an excellent conductor of electricity.

A
  • It has Delocalized electrons,

- Able to move

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14
Q

Explain, in terms of its structure and bonding, why graphene has a high melting point (2)

A
  • Covalent bonds,

- Many /strong / hard to break / need a lot of energy to break

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15
Q

Name the type of bonding in the element sodium

A

Metallic

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16
Q

Suggest why titanium can be hammered into different shapes.

A

Layers can slide over each other

17
Q

Suggest why these objects with different shapes have similar strengths

A

Strong metallic bonding re-formed

18
Q

Explain, in terms of its structure and bonding, why titanium has a high melting point. (2)

A
  • positive ions and delocalised electrons are attracted,

- strong attraction

19
Q

Magnesium oxide (MgO) has a melting point of 3125 K.
Predict the type of crystal structure in magnesium oxide and suggest why its melting point is high.
Type of crystal
Explanation

A
  • giant ionic,

- strong attraction between oppositely charged ions

20
Q

Explain why the melting point of sodium chloride is high

A
  • ionic bond,

- strong attraction between ions of opposite charges

21
Q

Explain in terms of bonding why KBrF has a high melting point

A
  • ionic bond,

- strong forces of attraction between oppositely charged ions

22
Q

Explain, in terms of structure and bonding, why the melting point of carbon is high (3)

A
  • macromolecular,
  • covalent bonds in the structure,
  • covalent bonds need a lot of energy to break
23
Q

Describe the bonding in a metal (2)

A

-positive ions attracted to delocalized electrons

24
Q

Explain each of these properties of diamond and graphite in terms of structure and
bonding. (6)

A

Diamond

  • atoms in diamond joined to 4 other carbon atoms forming a tetrahedral shape
  • diamond is hard and strong bcoz of its 3D shape,
  • giant covalent structure

Graphite

  • giant covalent structure
  • atoms in graphite joined to 3 other carbon atoms forming a Trigonal planar shape,
  • graphite is soft as layers can slide over each other
25
Q

Give one other difference in the properties of diamond and graphite.

A

diamond is non-conductor of electricity, graphite is conductor

26
Q

Why do diamond and graphite both have high melting points ?

A
  • giant covalent structure

- strong covalent bonds

27
Q

Why is graphite a good conductor of electricity?

A

It has delocalized electrons

28
Q

Why is graphite soft ?

A

Layers can slide over each other

29
Q

Describe the bonding in a crystal of iodine (2)

A
  • van der waals between molecules,

- covalent bonds between atoms

30
Q

In terms of its structure and bonding, suggest why graphite has a very high melting point (2)

A
  • macromolecular

- strong covalent bonds

31
Q

State the type of structure present in each case and explain why the melting point of diamond is so high.

A

-diamond is a macromolecular

C-C bonds need to be broken which takes a lot of energy bcoz bonds are strong

32
Q

Describe the bonding in, and the structure of, sodium chloride and ice

A
  • NaCl is ionic,
  • strong attraction between ions of opposite charge
  • covalent bonds between atoms in water
  • hydrogen bonding between water molecules
  • covalent bonds in ice are strong
  • tetrahedral
33
Q

Explain how the ions are held together in solid sodium metal

A

Strong attraction between positive ions and delocalized electrons

34
Q

Explain how the ions are held together in solid sodium chloride.

A
  • ionic bond,

- strong attraction between ions of opposite charge

35
Q

Compare the electrical conductivity of solid sodium metal with that of solid sodium chloride. Explain your answer.
Comparison,
Explanation

A
  • sodium conducts and NaCl doesn’t,
  • sodium has delocalized electrons that carry charge,
  • ions cannot move in NaCl but can when molten
36
Q

State the type of crystal structure for each of iodine and graphite.

A

Iodine- molecular ,

Graphite- giant covalent/macromolecular

37
Q

Describe the structure of and bonding in graphite and explain why the melting point of graphite is very high.

A
  • Layers of C-C bond connected by covalent bonds,
  • van der waals forces between layers,
  • strong covalent bonds need to be broken down
38
Q

Explain why iodine vaporises when heated gently

A

Van der waals forces between molecules are weak