Bonding and Structure

Question 1

What is ionic bonding?

Answer 1

The electrostatic attraction between positive and negative ions

Question 2

What are giant ionic lattices?

Answer 2

It is a regular, repeated arrangement of ionic compound

Question 3

Effect of structure and bonding of ionic compounds on - melting point?

Answer 3

The electrostatic attraction between anions and cations is very strong, so it takes a lot of energy to overcome. The greater the ionic charges the stronger the attraction

Question 4

Effect of structure and bonding of ionic compounds on solubility?

Answer 4

The polarity of water makes it attracted to the anions and cations

Question 5

Effect of structure and bonding of ionic compounds on electrical conductivity?

Answer 5

Ions can only conduct electricity when its ions are free to move (in a liquid/aqueous)

Question 6

What is covalent bonding?

Answer 6

The electrostatic attraction between the shared pair of electrons and the nuclei of the bonded atoms

Question 7

What is dative covalent bonding?

Answer 7

A covalent bond in which both of the electrons come from the same atom

Question 8

What is average bond enthalpy?

Answer 8

measures the energy required to break a bond

Question 9

How is the shape of molecules determined (electron pair repulsion etc.)?

Answer 9

The electron pairs repel from each other so are situated at furthest distance apart from each other around the nuclei

Question 10

What are the names of the shapes of molecules and ions with up to 6 electron pairs?

Answer 10

• 2 pairs - linear - 180
• 3 pairs - trigonal planar - 120
• 2 pairs, lone pair - non linear - <120
• 4 pairs - tetrahedral - 109.5
• 3 pairs, lone pair - pyramidal - 107
• 2 pairs, 2 lone pairs - non linear - 104.5
• 5 pairs - trigonal bipyramidal - 90, 120
• 6 pairs - octahedral - 90

Question 11

What is electronegativity?

Answer 11

the measure of the tendency of an atom to attract a bonding pair of electrons, measured using the Pauling Scale

Question 12

What is a polar bond?

Answer 12

A molecule with a difference of 0.4 electronegativity has a dipole, a molecule with an overall dipole is polar

Question 13

What is a permanent dipole?

Answer 13

Also described as polar, it is due the electronegativity differences of atoms in a molecule

Question 14

What is a polar molecule?

Answer 14

molecule that contains an overall polar dipole

Question 15

What is a dipole?

Answer 15

Occur due to the unequal sharing of electron meaning one area is more negative.

Question 16

How do permanent dipole-dipole interactions affect intermolecular forces?

Answer 16

the d+ and d- charges in polar molecules cause weak electrostatic forces of attraction between molecules, they happen in addition to induced dipoles

Question 17

How do induced dipole-dipole interactions affect intermolecular forces?

Answer 17

Electrons are moving around the atom very quickly, and at any particular moment one side will be more negative, so it will have a temporary dipole. This causes a temporary dipole in another neighbouring atom

Question 18

What is hydrogen bonding?

Answer 18

Strongest intermolecular force, happens when a hydrogen is covalently bonded with a nitrogen, oxygen or flourine. The bond is very polarised, so much that a weak bond is formed between a hydrogen or one molecule and a N, O or F of another

Question 19

Why is the density of ice smaller than water?

Answer 19

in ice molecules of H₂O are held in a lattice, when it melts the hydrogen bonds are broken, so water has less of them.

Question 20

What does water have a relatively high melting and boiling point?

Answer 20

Due to the strength of the intermolecular forces in hydrogen bonds

Question 21

What are simple molecular lattices?

Answer 21

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Question 22

Effect of structure and bonding of covalent compounds on melting points?

Answer 22

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Question 23

Effect of structure and bonding of covalent compounds on boiling points?

Answer 23

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Question 24

Effect of structure and bonding of covalent compounds on solubility?

Answer 24

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Question 25

Effect of structure and bonding of covalent compounds on electrical conductivity?

Answer 25

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