4.1 Ionic bonding and strcuture

Question 1

what are the 3 types of intramolecular bonds?

Answer 1

1. ionic
2. covalent
3. metallic

Question 2

define ionic bonding

Answer 2

the electrostatic attraction between oppositely charged ions

Question 3

when are ions formed?

Answer 3

when atoms lose or gain electrons to become cations or anions

Question 4

whats the difference between cations and anions?

Answer 4

cations are ions with a positive charge
anions are ions with a negative charge

Question 5

what type of elements are typically cations?

Answer 5

metals

Question 6

what type of elements are typically anions?

Answer 6

non-metals

Question 7

how do you know if a compound has an ionic bond?

Answer 7

• look at the electronegativity difference of the element
• if it is greater than 1.8, then that means that they do form an ionic bond

Question 8

define isoelectric

Answer 8

• having or involving no net electric charge or difference in electrical potential
• having the same electron configuration
• basically having the same number of electrons

Question 9

what is the difference between a solid ionic compound and a molten ionic compound?

Answer 9

solid - forms a rigid crystal lattice as bonds exist between all ions in every direction
molten - no lattice as ions are free to move

Question 10

what are the 4 properties of ionic compounds?

Answer 10

1. high melting point
2. volatility
3. solubility
4. conductivity

Question 11

why does ionic compounds have such high melting points?

Answer 11

• due to the strong electrostatic force of attraction between the ions in their lattices
• ionic compounds require large inputs of energy to break apart these forces

Question 12

describe the volatility of ionic compounds

Answer 12

• refers to the ease at which a substance vaporizes
• due to the strong electrostatic attraction, ionic compounds have a very low volatility

Question 13

describe the solubility of ionic compounds

Answer 13

• ionic compounds dissolve in polar solvents but not in non-polar solvents
• only solvents which contain molecules with partial charge can dissolve ionic compounds
• these partial charges can pull individual ions from the lattice

Question 14

describe the conductivity of ionic compounds and explain why can’t they conduct electricity sometimes

Answer 14

• ionic compounds cannot conduct electricity in solid state as the ions are fixed in place
• when molten, the ions can move freely, which allows the molten compound to conduct electricity

Question 15

explain, with reference to structure and bonding, why ionic compounds melt at high temperatures (3)

Answer 15

• ionic compounds form a crystal lattice
• they contain many strong ionic bonds/ electrostatic attractions between oppositely charged ions
• lots of energy to break the ionic bonds

Question 16

state and explain the situation in which ionic compounds conduct electricity

Answer 16

• when they are molten
• when they are aqueous
• ions are free to move and carry charge