Chemistry

• Fuels are dense repositories of energy that are consumed to provide energy such as heating, transportation and electrical generation.
• Fuel when in contact to oxygen in the air generate heat that catalyze chemical energy.
• A combustion reaction is a chemical reaction in which a fuel undergoes oxidation by reacting with an oxidising agent, resulting in the release of energy (usually in the form of heat).
• The general equation for combustion reactions is FUEL + OXYGEN → CARBON DIOXIDE + WATER VAPOR + HEAT ENERGY
• Combustion reactions can be represented using balanced equations.
• Incomplete combustion occurs when there isn't enough oxygen present to fully burn all the carbon atoms in the fuel.
• Carbon monoxide is produced during incomplete combustion.
• Oxygen is required for complete combustion.
• sparks plug ignites mixture that produces heat and powers the engine.
• Fuel-air ratio refers to the amount of air needed to completely burn one unit of fuel.
• Compression ratio: the higher the compression ratio
• When compression ratio reach the highest point, knocking occurs that makes the engine less powerful and less efficient.
• Higher compression ratios lead to higher knocking.
• knocking can be avoided with the use of special fuels with octane numbers
• The higher the octane rating, the more resistant it is to knocking.
• The calorific value of fuel is an essential property that determines the amount of heat energy generated from a given quantity of fuel.
• Foods with high calorific value produce more energy.
• The First Law of Thermodynamics states that energy cannot be created or destroyed; it can only be converted from one form to another.
• Energy transfer occurs when there are changes in temperature, pressure, volume, and state (solid/liquid/gas).
• heat flow
• heat is the energy that is transfered from something.
• system is a body of matter and/or radiation separate from its surroundings
• In an open system there is an exchange of mass or energy with its surroundings.
• isolated systems have neither mass nor energy transferred between them and their surroundings.
• In a closed system there is no transfer of mass but it allows the transfer of heat or energy.
• exothermic process is the release of energy from the system to its surroundings.
• Endothermic process is the process in which energy is absorbed by the system from its surroundings.
• The first law of thermodynamics states that energy cannot be created or destroyed, only transformed into different forms.
• When energy is absorbed by the system "q" (heat) is positive.
• When energy is released by the system "q" (heat) is negative.
• ∆u = q + w

  Change of internal energy = Heat + Work done
• When work is done by the system, W (work) is positive.
• When work is done ON the system, W (work) is negative.
• The zeroth law of thermodynamics states that if two bodies are each in thermal equilibrium with some third body, then they are also in equilibrium with each other.