Calculations using Ar, Mr and Moles

Question 1

What is Ar?

Answer 1

Atomic mass (compared to carbon)

Question 2

What is Mr?

Answer 2

Relative molecular mass (total of all the atomic masses)

Question 3

What is a mole?

Answer 3

1 mole = 6.022x10^23 particles

Question 4

What is mass?

Answer 4

The amount of matter

Question 5

Write the 3 equations linking mass, Mr and moles?

Answer 5

Mr x moles = mass
mass / Mr = moles
mass / moles = Mr

Question 6

EQUATION SHIT

Answer 6

LEARN IT

Question 7

What is the yield?

Answer 7

The amount of substance you get out as a proportion of which you put in

Question 8

What is the method for calculating the mass of a product? (Theoretical Maximum Yield)

Question 9

Name the two types of bonding?

Answer 9

The stealing of electrons (ionic) and the sharing of electrons (covalent and metallic)

Question 10

Why are the Noble gases exceptionally stable?

Answer 10

They have full electron shells

Question 11

What is an ion?

Answer 11

An element which has gained or lost electrons (ions are formed to make sure the atom has a full outer shell)

Question 12

What charge does the loss of electrons give?

Answer 12

Positive

Question 13

What charge does the gain of electrons give?

Answer 13

Negative

Question 14

What is the octet rule?

Answer 14

2 electrons in the first shell, 8 in the rest

Question 15

What does a full outer shell mean?

Answer 15

The ion/atom is stable

Question 16

What happens when a metal reacts with a non-metal?

Answer 16

The metal atom loses electrons and the non-metal gains - forming an ionic compound

Question 17

Oppositely charged ions do what?

Answer 17

Attract like magnets - this force of attraction is an ionic bond

Question 18

Why do metal atoms form +ve ions and non-metals -ve?

Answer 18

It takes less energy

Question 19

What is a lattice?

Answer 19

An arrangement of ions so that each +ve ion is surrounded by -ve ions and vice versa - this causes ions to form crystals, held together by electrostatic forces

Question 20

Why do ionic lattices have high melting/boiling points?

Answer 20

Have lots of electrostatic bonds - all must be broken; this takes a lot of energy

Question 21

What does molten mean?

Answer 21

A substance which has been melted (thus a liquid)

Question 22

Why can ionic lattices not conduct electricity when in a solid state?

Answer 22

The ions can’t move

Question 23

Why can ionic lattices conduct electricity when molten?

Answer 23

The ions are no longer held in place - can move

Question 24

What is covalent bonding?

Answer 24

Bonding between 2 non-metals

Question 25

What is metallic bonding?

Answer 25

Bonding between 2 metals

Question 26

What is ionic bonding?

Answer 26

Bonding between a metal and a non-metal

Question 27

Why do covalent compounds tend to have low melting/boiling points?

Answer 27

Each molecule is separate, few forces of attraction between molecules, not much energy is required, weak inter-molecular forces

Question 28

Describe metallic bonding?

Answer 28

Metal atoms donate their outer shell electrons to form a sea of delocalised electrons. The delocalised electrons attract the +ve metal ions with strong electrostatic attaractions that keep them together