Topic 1 - Key Concepts

Question 1

Chlorine Formula

Answer 1

Cl2

Question 2

Ammonia formula

Answer 2

NH3

Question 3

Ammonium ion

Answer 3

NH4+

Question 4

Nitrate ion

Answer 4

NO3-

Question 5

Sulfate ion

Answer 5

SO4 2-

Question 6

Hydroxide

Answer 6

OH-

Question 7

Carbonate ion

Answer 7

CO3 2-

Question 8

Ionic equation

Answer 8

Symbol equation but spectator ions are removed

Question 9

Hazard

Answer 9

Anything with the potential to cause harm

Question 10

Risk

Answer 10

Is the probability of someone being harmed

Question 11

Oxidising symbol

Answer 11

Provides oxygen which allows other materials to burn.

Question 12

Harmful

Answer 12

‘!’ Cause irritation

Question 13

Environmental hazard

Answer 13

Harmful to organisms and the environment

Question 14

Toxic

Answer 14

Can cause death. By swallowing, breathing, contact.

Question 15

Corrosive

Answer 15

Destroys materials including living tissue.

Question 16

First atomic structure

Answer 16

John Dalton, everything is made up of solid spheres.

Question 17

‘Plum pudding model’

Answer 17

JJ Thompson. Discovered charge and mass. He concluded there must be electrons.

Question 18

Rutherford

Answer 18

Gold leaf experiment, concluded there is a positive nucleus surrounded by moving electrons.

Question 19

Final atomic structure.

Answer 19

Bohr suggested energy levels with fixed orbits. Each shell has a fixed energy.

Question 20

Relative mass of an electron

Answer 20

0.0005 (1/2000)

Question 21

Relative atomic mass (Ar)

Answer 21

Average mass of one atom compared to the 1/12 of the mass of Carbon-12

Question 22

Dmitri Mendeleev

Answer 22

Sorted into groups based on properties. He ordered using Atomic Mass. He left gaps for undiscovered elements and predicted their properties (ekasilicon and germanium). Tellurium and Iodine were the wrong way around.

Question 23

Ionic Bonding

Answer 23

Metal and Non-metal react. Metal loses electrons forming a Cation. Non-metal gains electrons forming an anion. They are held together by electrostatic attraction.

Question 24

Ionic lattice

Answer 24

Giant,crystalline, Strong electrostatic attraction in all directions.

Question 25

Limitations of 2D representations (displayed formula)

Answer 25

Don’t show the shape or size of atoms.

Question 26

Dot and cross diagrams limitations

Answer 26

Don’t show arrangement or size.

Question 27

3D model limitations

Answer 27

Only show the outer layer of the substance.

Question 28

Ball and stick limitations

Answer 28

Misleading with gaps between atoms where electrons interact, don’t show correct scale.

Question 29

MP and BP of covalent substances

Answer 29

Low, as intermolecular are weak.

Question 30

As molecules get bigger their..

Answer 30

Intermolecular forces require more energy to break them.

Question 31

Giant covalent properties

Answer 31

Strong Covalent bonds. Very high MP and BP. Don’t conduct. Insoluble.

Question 32

Diamond

Answer 32

Each carbon is bonded 4 times. Require lots of energy to break bonds. Rigid lattice making it very hard. Can’t conduct.

Question 33

Graphite

Answer 33

Each carbon bonded 3-times. The extra electron is delocalised making it conductive. Layers can move making it a good lubricant.

Question 34

Graphene

Answer 34

A single layer of graphite. Sheet of carbon hexagons. One atom thick, 2D.

Question 35

Fullerenes

Answer 35

Form molecules of carbon shaped in tubes or balls. Made up of carbon Hexagons (sometimes pentagons and heptagon).

Question 36

Uses of Fullerenes

Answer 36

1. Delivering drugs to cells. ‘Cage’ other molecules. 2. Very large surface area used for industrial catalysts as molecules can be attached to them. 3. Nanotubes can be used (graphene cylinders) to strength materials as they’re strong and light

Question 37

If mass increases

Answer 37

Reactant was a gas

Question 38

If mass decreases

Answer 38

Product is a gas.

Question 39

Find molecular formula from empirical formula

Answer 39

Find Mr of empirical formula. Mr of compound / Mr of empirical formula Multiply empirical formula

Question 40

Moles =

Answer 40

Mass | Mr

Question 41

Avogadro’s constant

Answer 41

6.02 x 10^23

Question 42

Concentration

Answer 42

Mass / volume

Question 43

1dm^3

Answer 43

1000cm^3

Question 44

Empirical formula experiments.

Answer 44

Weigh crucible. Add magnesium, weigh again, subtract from original to calculate the mass. Heat the crucible with lid (preventing bits escaping) until all ribbon has turned white. Cool and reweigh crucible with contents. Calculate the mass of magnesium oxide. Calculate moles of added oxygen and original magnesium.

Question 45

Limiting reactant

Answer 45

The reaction stops once one of the reactants have been used up. Amount of product ∝ limiting reactant.

Question 46

Find balance equation from masses

Answer 46

Calculate the number of moles Divide through by the lowest number of moles. Make it integer. Put into equation.