chem paper 2

Sustainable Development

Development that meets the needs of current generations without compromising the ability of future generations to meet their own needs.

Potable Water Production

The process of producing drinking water through appropriate sourcing, filtration to remove solids, and sterilisation to kill microbes.

Sterilising Agents

Substances used to kill harmful microorganisms in potable water, including chlorine, ozone, and ultraviolet light.

Chlorine

A toxic gas used as a sterilising agent for potable water that requires careful monitoring of the amount added.

Ultraviolet Light

A method of sterilisation that avoids adding chemicals but is more expensive.

Desalination

The process of removing salt from seawater, commonly achieved through distillation or reverse osmosis methods.

Reverse Osmosis

A desalination process where seawater is forced through a membrane that allows only water molecules to pass.

Wastewater Production

The generation of used water from urban lifestyles and industrial processes that needs treatment before environmental discharge.

Sewage Treatment Processes

Includes screening, sedimentation to produce sludge and effluent, anaerobic digestion of sludge, and aerobic treatment of effluent.

Phytomining

A method of extracting metals from soil using plants which absorb metal compounds, harvested and burned to yield metal-rich ash.

Bioleaching

Using bacteria to generate leachate solutions containing metal compounds from ores.

Life Cycle Assessments (LCAs)

Evaluations that assess a product's environmental impact during various stages including extraction, manufacturing, usage, and disposal.

Resource Reduction Techniques

Methods such as reducing use, reusing, and recycling materials to minimize resource consumption and environmental impacts.

Recycling Advantages

Benefits such as reduced waste, less pollution, conserved resources, and job creation.

Recycling Disadvantages

Challenges including collection difficulties, transport costs, and sorting issues of recyclable materials.

Corrosion

The destruction of materials due to chemical reactions with environmental substances, such as rusting.

Corrosion Prevention Methods

Techniques such as greasing, painting, or electroplating to create barriers that protect metals from corrosion.

Sacrificial Protection

Using a more reactive metal to corrode instead of a less reactive one, thereby protecting the less reactive one from corrosion.

Bronze

An alloy of copper and tin, typically used for statues and decorative items.

Brass

An alloy of copper and zinc, commonly used in plumbing fixtures and fittings.

Gold Alloys

Gold used in jewelry, typically alloyed with silver, copper, and zinc, with purity measured in carats.

Aluminium-Magnesium Alloys

Lightweight alloys used in aerospace applications.

Steel

Alloys of iron with varying amounts of carbon and other metals, used for various applications from construction to manufacturing.

Polymers Properties Determination

The properties of polymers are influenced by the monomers used and the conditions of their formation.

Thermosoftening Polymers

Polymers that soften on heating and can be remoulded, characterized by weak intermolecular forces.

Thermosetting Polymers

Polymers that do not melt on heating and have strong cross-links between molecules.

Soda-Lime Glass

The most common glass, made from a mixture of sand, sodium carbonate, and limestone.

Clay Ceramics Production

The process of making pottery and bricks by shaping wet clay and heating it in a furnace.

Composite Formation

Creations where fibers or fragments of one material are held together by a binder or matrix material.

Haber Process

A method for synthesizing ammonia from hydrogen and nitrogen gases at high temperature and pressure using an iron catalyst.

NPK Fertilizers

Fertilizers containing compounds of nitrogen, phosphorus, and potassium used to enhance agricultural productivity.

Phosphate Rock Utilization

Phosphate rock is used to produce phosphoric acid and various calcium phosphate compounds for fertilizers.

Proportions of gases in modern atmosphere

About 80% Nitrogen (N2), 20% Oxygen (O2), with small quantities of carbon dioxide (CO2), water vapor (H2O), and noble gases.

Earth’s early atmosphere

Formed from volcanic activity, primarily composed of carbon dioxide (CO2), nitrogen (N2), methane (CH4), ammonia (NH3), and water (H2O).

Photosynthesis equation

6 CO2 + 6 H2O → C6H12O6 + 6 O2; process by which plants produce oxygen.

Greenhouse effect

A natural process that maintains Earth's temperature by trapping heat from short wavelength solar radiation.

Greenhouse gases

Gases that contribute to the greenhouse effect, including water vapor, carbon dioxide, and methane.

Effects of global climate change

Include sea level rise, severe storms, altered rainfall patterns, and impact on wildlife and food production.

Carbon footprint

Total amount of carbon dioxide and greenhouse gases emitted throughout the lifecycle of a product or service.

Actions to reduce carbon footprint

Include increased use of alternative energies, energy conservation, carbon capture, and carbon offsetting.

Problems of reducing carbon footprint

Include economic costs, public resistance to lifestyle changes, and lack of international cooperation.

Advantages of complete combustion

Less soot produced, more heat released per gram of fuel, and no poisonous carbon monoxide formed.

Pollution from combustion

Gases released include carbon dioxide, water vapor, carbon monoxide, sulfur dioxide, and nitrogen oxides.

Issues with sulfur dioxide and nitrogen oxides

Cause respiratory problems and contribute to acid rain, damaging both plants and buildings.

Impact of particulates

Reduce sunlight reaching Earth's surface, causing global dimming and health issues, particularly lung damage.

Importance of oxygen in atmosphere

Produced by plants and algae, vital for life, allows for respiration and contributes to the ozone layer.

Fossil fuel combustion sources

The major source of carbon dioxide emissions, primarily from transportation, industry, and energy production.

Pure Substance

A single element or compound, not mixed with any other substance.

Formulation

A mixture of compounds in measured quantities designed as a useful product.

Example of Formulations

Includes fuels, cleaning agents, paints, medicines, alloys, fertilizers, and foods.

Paper Chromatography

A method used to separate components of a mixture based on their different affinities for a solvent and stationary phase.

Stationary Phase

The paper in paper chromatography that does not move.

Mobile Phase

The solvent in paper chromatography that travels up the paper.

Rf Value

The ratio of the distance traveled by the compound to the distance traveled by the solvent front in chromatography.

Test for Hydrogen

Pop with burning splint over gas.

Test for Oxygen

Glowing splint relights.

Test for Carbon Dioxide

Turns limewater (Ca(OH)2) milky.

Test for Chlorine

Bleaches damp litmus paper and makes it white.

Flame Test for Lithium

Produces a crimson red flame.

Flame Test for Sodium

Produces a yellow flame.

Flame Test for Potassium

Produces a lilac flame.

Crude oil

A mixture of compounds; a fossil fuel consisting of the remains of ancient biomass.

Finite resource

A resource that cannot be replaced as it is used up.

Homologous series

Series of compounds with the same general formula, same functional groups, and similar chemical properties.

Combustion of hydrocarbons

An exothermic reaction when hydrocarbons react with oxygen.

Complete combustion

Produces carbon dioxide and water, fully oxidizing carbon and hydrogen atoms.

Incomplete combustion

Produces carbon or carbon monoxide and water due to insufficient oxygen.

Physical properties of alkanes

First few are gases, then liquids, then solids; boiling points and viscosity increase with size.

Fractional distillation

A process to separate hydrocarbons based on different boiling points.

Catalytic cracking

A process where reactants are heated to vapor and passed over a hot catalyst.

Steam cracking

A method where reactants are vaporized and mixed with steam at high temperatures.

Addition reactions of alkenes

Reactions that convert carbon-carbon double bonds into single bonds by adding atoms.

Hydrogenation

Addition of hydrogen across a double bond requiring high temperatures and a nickel catalyst.

Hydration

Addition of water to a double bond that requires high temperature, pressure, and phosphoric acid as a catalyst.

Halogen addition

The process of adding halogens (Br2/Cl2/I2) across the carbon-carbon double bond.

Characteristics of alcohols

Dissolve in water to form neutral solutions, react with sodium, burn in oxygen, and form esters.

Fermentation conditions

30°C, aqueous glucose solution, absence of air, with yeast added.

Fermentation equation

C6H12O6 → 2 CH3CH2OH + 2 CO2.

Carboxylic acids

Dissolve in water to form acidic solutions, react with metal carbonates, alcohols, and metals.

Weak acids

Carboxylic acids are partially dissociated in water, making them weaker than strong acids.

Ester

An organic compound containing a -COO- functional group formed from a carboxylic acid and an alcohol.

Addition polymerisation

A reaction where molecules with C=C bonds join together to form a long chain polymer.

Polyethylene

An addition polymer used for plastic bags.

Polytetrafluoroethene (PTFE)

An addition polymer used for non-stick kitchenware.

Polyvinylchloride (PVC)

An addition polymer used for water pipes.

Repeating unit of a polymer

The smallest structure that, upon numerous translations, yields the structure of the polymer.

Condensation polymer

A polymer formed via condensation polymerization, releasing a small molecule such as H2O or HCl.

Polyester example

Terylene, commonly used in textiles.

Polyamide example

Nylon, used in fabrics and materials.

Amide bond

Similar to an ester bond but with oxygen replaced by nitrogen.

Amino acid

An organic compound containing both a carboxylic acid functionality and an amine functional group.

Protein synthesis

A process involving condensation polymerization of amino acids to form proteins.

Polypeptides

Shorter chains made from amino acids through condensation polymerization.

Carbohydrates

Organic molecules made of carbon, hydrogen, and oxygen; includes starch and cellulose.

DNA

Deoxyribonucleic acid, the material that makes up chromosomes and stores genetic information.

Rate of Reaction

The speed at which a chemical reaction occurs, calculated by the amount of reactants used or products formed over time.

Units for Rate of Reaction

Commonly expressed as g/s, cm3/s, or mol/s; generally follows the format mass/time, volume/time, moles/time.

Ways to Measure Rate of Reaction

Common methods include monitoring loss in mass of reactants, volume of gas produced, and time for a solution to become opaque.

Collision Theory

The theory stating that chemical reactions occur when reacting particles collide with sufficient energy to overcome activation energy.

Factors Affecting Rate of Reaction

Five main factors include concentration of reactants, pressure of gases, surface area, temperature, and the presence of catalysts.