Chemistry Notes for Semester 2 Year 10

Energy

Energy

Energy is the capacity to do work. It can be transferred and transformed but not created nor destroyed.

2 Main Categories of Energy

1. Kinetic - Movement

2. Potential - Stored

Energy Consumption

All the energy required/used to perform an action (KwH)

Direct Energy

Energy you use yourself

Examples:

• Lighting

• Heating

• Fuel for Transportation

• Electricity

• Electrical Appliances

• Cooking

Indirect Energy

Energy used to produce items that you purchase/use

Examples:

• Manufacturing Machine

• Infrastructure for Supply

• Mining Operations

• Machines used to make clothes

• Growing of food

• Cleaning/Filtering of water drunk

• Production of any consumer goods
  

Fossil Fuels

High-Energy, non-renewable fuels formed during the carboniferous period

3 Types of Fossil Fuels

• Coal

• Crude

• Natural Gases

All alkanes. CO₂ Levels Increase when Burnt.

Coal

Formed from plants that hardened due to pressure and heat (over millions of years) in swamps. Layers of sand and mud reduce the oxygen by sealing, which prevents decomposition.

Crude Oil

Micro-organisms which high carbon content (exoskeltons) fall to the bottom of the ocean. Layers of sand and mud reduce the oxygen by sealing, which prevents decomposition.

Natural Gas

Micro-organisms which high carbon content (exoskeltons) fall to the bottom of the ocean. Layers of sand and mud reduce the oxygen by sealing, which prevents decomposition. Cooked for longer with more pressure.

Greenhouse Effect Steps

1. Earth’s Surface absorbs visible lights

2. Earth’s surface increase in temperature

3. Earth emits infrared waves

4. Most infrared waves passes through the atmosphere but some infrared waves are absorbed by greenhouse gas molecules

5. Gas molecules increase in vibrational energy, causing increases in collisions and emissions between particles

6. Kinetic Energy between particles increase

7. Temperature of atmosphere increases

Common Greenhouse Gases

• Carbon Dioxide CO₂

• Methane CH₄

• Nitrous Oxide N₂O

• Hydrofluorocarbons HCF_s

• Sulfur Hexafluorides SF₆

• Water Vapour H₂O

• Perfluorocarbons PCF_s

• Nitrogen Trifluoride NF₃

Effects of Greenhouse Gases (Global and Local)

Global

• Climate Change → Hotter Temperature, More Sever Storms, Increased Drought, Rising Oceans, Extinction of Species and Food Security

• Respiratory Issues → Smog, Air Pollution

Local

• Agriculture

• Floods and Fires

Organic Chemistry Definition

Study of carbon-containing compounds with 4 possible bonds. Requires a chemical reaction (Except CO₂).

Fractional Distillation Definition

Process used to separate a mixture of liquids that have different boiling points.

Fractional Distillation Steps

1. Oil is heated to 350-400^oC, where it evaporates and is pumped into a tall tower called a fractioning coloumn

2. The column hotter towards the bottom, cooling and condensing the vapour

3. Heavy fractions have a higher boiling point while lower have lower boiling points.

Petroleum Gas (Temperature and Uses)

<25^oC, Heating + Cooking

Petrol (Temperature and Uses)

>25^oC - 60^oC, Cars (after removing impurities)

Napatha (Temperature and Uses)

>60 - 180^oC, Medicine + Paint Thinner

Kerosene (Temperature and Uses)

>180 - 220^oC, Airplane fuel + Central Heat Systems

Diesel (Temperature and Uses)

>220 - 250^oC, Diesel Cars + Buses + Boats

Fuel Oil (Temperature and Uses)

>250 - 300^oC, Fuel for Boilers + Power Stations + Container Ships

Lubricating Oil (Temperature and Uses)

>300 - 350^oC, Lubrication of machines

Bitumen (Temperature and Uses)

>350^oC, Roads + Waterproof Roof