Chemistry Level 7 - Inorganic Chemistry

Question 1

what are the physical properties of ionic substances?

Answer 1

• high melting and boiling points
• conduct electricity when molten in aqueous solution but not when solid
• mostly soluble in water

Question 2

what are the physical properties of covalent molecules?

Answer 2

• low melting and boiling points
• do not conduct electricity
• not soluble in water

Question 3

what are the physical properties of metals?

Answer 3

• generally have high melting and boiling points
• conduct electricity when solid and molten
• not soluble in water

Question 4

why is oil not soluble in water?

Answer 4

• water molecules are polar covalent
• aggregate together via hydrogen bonding
• causes non-polar molecules to squeeze out

Question 5

why is water a liquid at room temperature?

Answer 5

• water molecules are polar covalent with a slightly negative oxygen atom and 2 slightly positive hydrogen atoms
• hydrogen bonding occurs between the slightly positive hydrogen atom of one molecule and the slightly negative oxygen atom of another water molecule
• water molecules joined by strong hydrogen bonds therefore higher boiling point and liquid at room temperature

Question 6

define Le Chatelier’s Principle

Answer 6

if a change occurs in a system at equilibrium, then equilibrium will shift to counteract that change

Question 7

what does dynamic equilibrium mean?

Answer 7

the rate of the forward reaction is equal to the rate of the reverse reaction

Question 8

what is a covalent bond?

Answer 8

electrostatic force of attraction between nuclei of 2 atoms and their shared pair of electrons

Question 9

what is an ionic bond?

Answer 9

electrostatic force of attraction between two oppositely charged ions

Question 10

what is a metallic bond?

Answer 10

electrostatic force of attraction between delocalised electrons and positive metal ions

Question 11

describe the structure of ionic substances

Answer 11

ionic structures consist of a solid giant lattice of repeating positive and negative ions

Question 12

describe the structure of covalent molecules

Answer 12

covalent molecules consist of small discrete groups of atoms held together by covalent bonds

Question 13

describe the structure of metals

Answer 13

metals consist of lattice structure of positive metal ions surrounded by a sea of delocalised electrons