5.2 what are properties of ionic substances

Question 1

structural properties of ionic compounds

Answer 1

ionic compounds have giant ionic crystal lattice structures

Question 2

describe the giant ionic crystal lattice structure

Answer 2

the lattice consists or large numbers of alternating positive and negative ions held together by electrostatic forces of attraction

Question 3

melting and boiling points of ionic compounds

Answer 3

have high melting and boiling points

Question 4

why do ionic compounds have high melting and boiling points

Answer 4

because the mutual electrostatic attraction between oppositely charged ions are strong, a large amount of energy is needed to overcome these forces

Question 5

what state are ionic compounds at room temperature

Answer 5

solid

Question 6

hardness of ionic compounds

Answer 6

ionic compounds are resistant to deforming and tend to be hard

Question 7

why are ionic compounds hard

Answer 7

the mutual electrostatic attraction between oppositely charged ions also make them resistant to deforming and tend to be hard as their attractive forces cause the ions to resist motion

Question 8

ionic compounds are hard but __

Answer 8

brittle

Question 9

why are ionic compounds known as hard but brittle

Answer 9

when enough force is applied, the ions move away from their lattice positions and ions of the same charge approach each other. the repulsive forces between ions of the same charge becomes larger than the attractive forces, and the lattice structure shatters. hence ionic compounds are hard but brittle

Question 10

solubility of ionic compounds

Answer 10

most ionic compounds are soluble in wares and insoluble in organic solvents

Question 11

what are ionic compounds said to be when dissolved in water

Answer 11

they are in the aqueous state

Question 12

electrical conductivity of ionic compounds

Answer 12

ionic compounds can conduct electricity in the liquid and aqueous states but not in the solid state

Question 13

describe the structure of ionic compounds in the solid state and explain why they cannot conduct electricity

Answer 13

when an ionic compound is in the solid state, the ions in the lattice are only able to vibrate about their fixed positions hence the ions are not mobile and cannot conduct electricity

Question 14

describe the structure of ionic compounds in the liquid (aqueous/ molten) state and explain why they are able to conduct electricity

Answer 14

when the compound is molten or in the aqueous state, the ions are mobile and can conduct electricity