extended notes

Question 1

What are the characteristics of solids?

Answer 1

Fixed shape/volume, strong intermolecular forces, incompressible, particles vibrate about fixed positions.

Question 2

What defines the properties of liquids?

Answer 2

Fixed volume, variable shape, weaker forces than solids, flow and take shape of container.

Question 3

What are the properties of gases?

Answer 3

No fixed volume/shape, negligible forces, easily compressed, random rapid movement.

Question 4

What is latent heat?

Answer 4

Energy used to change state without temperature change.

Question 5

What is diffusion and in which state of matter is it fastest?

Answer 5

Movement of particles from high to low concentration; faster in gases due to greater kinetic energy and space.

Question 6

Define an element.

Answer 6

Cannot be broken into simpler substances.

Question 7

What is a compound?

Answer 7

Fixed composition; chemically bonded.

Question 8

Define a mixture.

Answer 8

Variable composition; components retain properties.

Question 9

What is chromatography used for?

Answer 9

To separate components in a mixture based on their movement through a medium.

Question 10

What is a pure substance?

Answer 10

Has a sharp melting/boiling point.

Question 11

What does the proton number (Z) represent?

Answer 11

Atomic Number.

Question 12

Define nucleon number (A).

Answer 12

Protons + Neutrons.

Question 13

What are isotopes?

Answer 13

Atoms of the same element with different numbers of neutrons.

Question 14

What is relative atomic mass (Ar)?

Answer 14

Weighted mean of isotopes.

Question 15

What are ions?

Answer 15

Atoms that gain/lose electrons to form charged species.

Question 16

What does the group number in the periodic table indicate?

Answer 16

Number of outer electrons.

Question 17

What does the period number in the periodic table indicate?

Answer 17

Number of electron shells.

Question 18

List characteristics of transition metals.

Answer 18

• High melting/boiling points
• Variable valency
• Form coloured compounds
• Act as catalysts.

Question 19

What trend occurs across a period in the periodic table?

Answer 19

Increase in nuclear charge, atomic radius decreases.

Question 20

What trend occurs down a group in the periodic table?

Answer 20

Atomic radius increases, outer electrons further from nucleus.

Question 21

What are ionic lattices characterized by?

Answer 21

Strong electrostatic forces, high melting points.

Question 22

What defines covalent molecules?

Answer 22

Low melting/boiling points due to weak intermolecular forces.

Question 23

Describe giant covalent structures.

Answer 23

• Diamond: 4 bonds, hard, insulator
• Graphite: 3 bonds, layers, conductor.

Question 24

What is metallic bonding?

Answer 24

Explains conductivity and malleability of metals.

Question 25

What is polarity in chemistry?

Answer 25

Uneven sharing of electrons creates dipoles.

Question 26

Define a mole.

Answer 26

1 mole = 6.02 × 10²³ particles.

Question 27

How do you calculate moles from gas volume?

Answer 27

Volume/24 (dm³).

Question 28

What is a limiting reagent?

Answer 28

Substance that determines the amount of product formed.

Question 29

How is yield calculated?

Answer 29

% yield = (actual / theoretical) × 100.

Question 30

Differentiate between empirical and molecular formula.

Answer 30

Molecular = (Empirical × n).

Question 31

What is enthalpy change (ΔH)?

Answer 31

Negative for exothermic, positive for endothermic reactions.

Question 32

Define activation energy.

Answer 32

Minimum energy required for a reaction to occur.

Question 33

What is calorimetry used for?

Answer 33

To calculate energy released in experiments using q = mcΔT.

Question 34

What is an electrolyte?

Answer 34

Ionic substance that conducts electricity when molten or dissolved.

Question 35

What products are formed at the cathode during electrolysis?

Answer 35

Least reactive cation (e.g., H⁺ unless metal less reactive).

Question 36

What is produced at the anode during electrolysis?

Answer 36

Halide ion if present, otherwise OH⁻ (produces O₂).

Question 37

What is electroplating?

Answer 37

Process where an object at cathode is coated with metal from anode.

Question 38

List methods for measuring the rate of reaction.

Answer 38

* Gas syringe * Mass loss * Colour change.

Question 39

What is the effect of a catalyst on a reaction?

Answer 39

Provides alternative pathway with lower activation energy.

Question 40

True or False: Strong acids fully ionize in solution.

Answer 40

True.

Question 41

What are the solubility rules for nitrates?

Answer 41

All nitrates are soluble.

Question 42

What is the procedure for preparing salts using an insoluble base?

Answer 42

* Add excess solid to acid * Filtration * Evaporation.

Question 43

Define redox reactions.

Answer 43

Oxidation = loss of electrons, Reduction = gain of electrons.

Question 44

What conditions are necessary for rusting?

Answer 44

Water and oxygen.

Question 45

What is sacrificial protection?

Answer 45

More reactive metal corrodes instead of the protected metal.

Question 46

What are alloys?

Answer 46

Mixtures of metals for improved properties (e.g., stainless steel).

Question 47

What is the composition of air?

Answer 47

N₂ (78%), O₂ (21%), others (1%).

Question 48

List three pollutants found in air.

Answer 48

* CO * NOx/SO₂ * CFCs.

Question 49

What is the process for water treatment?

Answer 49

Sedimentation → Filtration → Chlorination.

Question 50

What test can determine the purity of water?

Answer 50

Boiling/melting point tests.

Question 51

What is the Contact Process used for?

Answer 51

Production of sulfuric acid.

Question 52

What are the steps in the Contact Process?

Answer 52

* S + O₂ → SO₂ * 2SO₂ + O₂ ⇌ 2SO₃ (450°C, 2 atm, V₂O₅ catalyst) * SO₃ + H₂SO₄ → H₂S₂O₇ → add H₂O → H₂SO₄.

Question 53

What are the uses of sulfur dioxide (SO₂)?

Answer 53

* Bleach * Preservative.

Question 54

What is produced when limestone decomposes?

Answer 54

Quicklime (CaO) and CO₂.

Question 55

How can you test for carbonates?

Answer 55

Add acid → fizzing → CO₂ turns limewater cloudy.

Question 56

What are the two main types of hydrocarbons?

Answer 56

* Alkanes: Saturated, single bonds (CnH2n+2) * Alkenes: Unsaturated, double bonds (CnH2n).

Question 57

What is fractional distillation used for?

Answer 57

Separates crude oil by boiling points.

Question 58

What is cracking in organic chemistry?

Answer 58

Breaks long chains into useful alkanes and alkenes.

Question 59

What are the two types of polymerization?

Answer 59

* Addition (from alkenes) * Condensation (di-functional monomers).

Question 60

What is the functional group of alcohols?

Answer 60

OH group.

Question 61

How is ethanol produced?

Answer 61

* Via fermentation * Hydration of ethene.

Question 62

What defines carboxylic acids?

Answer 62

Contain COOH group and are weak acids.

Question 63

What is the importance of accuracy and precision in experiments?

Answer 63

Ensures reliability and validity of results.

Question 64

List the types of variables in an experiment.

Answer 64

* Independent: Changed * Dependent: Measured * Control: Held constant.

Question 65

What is a line of best fit in graphing?

Answer 65

A line that best represents the data points.

Question 66

What are flame tests used for?

Answer 66

Identify metal ions based on flame color.

Question 67

What is the test for chlorides?

Answer 67

White precipitate with AgNO₃.

Question 68

What is the test for sulfates?

Answer 68

White precipitate with BaCl₂.

Question 69

What is the test for carbonates?

Answer 69

Bubbles with acid.