VCE YEAR 12 DECK Flashcards
ALL OF YEAR 12 (110 cards)
What is a fuel?
A substance that contains high energy content which can be easily be released and converted into other forms of energy.
What is stored energy called?
Enthalpy, or, H
what happens when bonds break/ form
break= energy is absorbed, endothermic i.e will feel cold
Form= Energy is released, exothermic i.e will feel hot.
Endothermic, products and reactants.
Products will have more energy than the reactants, energy has been absorbed. Enthalpy will be positive.
Exothermic, products and reactants.
Reactants will have more energy than products, energy has been released, will be negative.
Energy profile diagrams for endo and exo thermic (draw diagrams, check first book for answers)
How do you calculate activation energy?
highest point of diagram - where reactants start
How do you calculate enthalpy change
H of products- H of reactants.
Why do we need fuels?
We need fuels because they store energy that can be released for heat or power.
What are fossil fuels?
Fossil fuels are natural energy sources formed from the remains of ancient plants and animals over millions of years. The main types are coal, oil, and natural gas.
explain how we use coal
Coal is used to produce electricity by burning it to release chemical energy. When coal burns, it reacts with oxygen (C + O₂ → CO₂), releasing thermal energy. This thermal energy is used to heat water, creating steam that drives turbines connected to generators, producing electrical energy. In Australia, over 50% of electricity is generated this way. Instead of transporting coal directly, electricity is transmitted from power stations to homes and businesses through metal cables and wires
explain how we use petrol
Petrol is a fuel made from crude oil through fractional distillation, which separates different hydrocarbon mixtures. It contains compounds like octane. In a car engine, petrol burns (2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O), releasing energy that creates hot gases to push the pistons and move the car. Diesel is another fuel made from a different fraction of crude oil, with slightly longer hydrocarbon chains
explain how we use natural gas
Natural gas is a fossil fuel made mostly of methane, with small amounts of other hydrocarbons. It is found in underground reservoirs, petroleum deposits, or bonded to coal as coal seam gas (CSG). Natural gas is accessed by drilling, which allows it to flow to the surface. It is burned to produce heat or electricity, commonly used for cooking, heating homes, and generating power
Why cant we keep using fossil fuels?
They are burned to produce energy but release carbon dioxide, contributing to air pollution and climate change and also non-renewable meaning they are used up quicker than they are replenished.
What are biofuels?
Biofuels are renewable fuels made from plant materials like grains, sugarcane, vegetable oils, and waste. The three main types are bioethanol, biogas, and biodiesel. They can be used on their own or blended with fossil fuels, offering a more environmentally friendly alternative to traditional fuels.
What is biogas and what creates it and how is it made
Biogas is a gas made when bacteria break down organic waste without oxygen. It mostly contains methane and carbon dioxide. Biogas is created in digesters—tanks where waste like food scraps or plant material is broken down. It can be used for heating or making electricity, often at farms or sewage plants. Since it has less methane than natural gas, it produces less energy when burned
what other components are there of biogas?
CO2, Water, sulfates, nitrates etc.
What is biodiesel, what creates it and how is it made?
Biodiesel is a renewable fuel made by reacting vegetable oils or animal fats with alcohol (usually methanol) in a process called transesterification. This reaction breaks down fats into glycerol and ester molecules, which make up the biodiesel. The biodiesel can then be used in diesel engines as an eco-friendly alternative to petroleum diesel
What is an Esther linkage group?
In the context of fats and oils, the ester linkage is the bond between the fatty acid chains (acid part) and the glycerol molecule (alcohol part). This bond is what holds the triglyceride structure together. When fats or oils undergo transesterification to form biodiesel, these ester linkages are broken and reformed with alcohol (methanol or ethanol), creating biodiesel esters
What is bio ethanol, what creates it and how is it made
Bioethanol is a renewable fuel made by fermenting sugars, like glucose, found in plants such as sugar cane, wheat, or forest waste. During fermentation, glucose is converted into ethanol and carbon dioxide. The ethanol is then purified through distillation, where it’s separated from water. Although bioethanol is a cleaner fuel, its production still requires significant energy, so it’s not fully carbon-neutral.
What does renewability mean?
Means that it can be replenished as fast as it is used.
Advantages and disadvantages of coal
Advantages-* Large reserves
* Less easily transported than
liquid or gaseous fuels
* Relatively high energy content
disadvantages-* Non-renewable
* High level of emissions
Advantages and disadvantages of natural gas
Advantages-* More efficient than coal for
electricity production
* Easy to transport through pipes
* Relatively high energy content
disadvantages-* Non-renewable
* Limited reserves
* Polluting, but less than coal
and petrol
Advantages and disadvantages of biogas
Advantages-* Renewable
* Made from waste
* Reduces waste disposal
* Low running costs
* CO2 absorbed during
photosynthesis
disadvantages- * Low energy content
* Supply of waste raw materials
limited
