Energy from fuels

Combustion

A fast thermochemical reaction requiring fuel, oxygen, and a source of ignition, producing heat and light.

Complete combustion

Occurs when fuels burn in excess oxygen, producing carbon dioxide and water.

Incomplete combustion

Happens when there is a limited supply of oxygen, producing carbon monoxide or soot along with water.

Oxidation

A reaction involving the addition of oxygen or the removal of hydrogen, characteristic of combustion.

Exothermic reaction

A reaction that releases heat, such as combustion.

Hydrocarbons

Organic compounds consisting of hydrogen and carbon, commonly used as fuels.

Biofuels

Renewable fuels made from organic compounds, such as bioethanol and biodiesel.

Greenhouse gas

Gases that absorb and emit radiation, contributing to the greenhouse effect and global warming.

Carbon monoxide

A colorless, odorless toxic gas produced from incomplete combustion, which can bind to hemoglobin in blood.

Activation energy

The minimum energy required for a reaction to occur.

Transesterification

A chemical process used to produce biodiesel from triglyceride oils and alcohol.

Specific energy

The amount of energy contained in a unit mass of a fuel.

Fossil fuels

Natural fuels, such as coal, oil, and natural gas, derived from the remains of ancient organisms.

Soot

Fine black particles produced from incomplete combustion, indicating high carbon content in fuels.

Methanol fuel cell

A type of fuel cell that uses methanol as fuel and produces carbon dioxide and water.

Hydrogen fuel cell

An electrochemical cell that converts hydrogen and oxygen into water, generating electricity.

Greenhouse effect

The warming of the Earth due to the trapping of heat by greenhouse gases in the atmosphere.

Carbon dioxide

A greenhouse gas produced when fuels are combusted, contributing to global warming.

Fermentation

A biological process that converts sugars into alcohol, used in the production of bioethanol.

Alkanes

Saturated hydrocarbons with the general formula CnH2n+2, commonly used as fuels.

Photosynthesis

The process by which green plants convert carbon dioxide and water into glucose and oxygen using sunlight.

Chemical equation for complete combustion of methane

CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)

What is combustion?

Combustion is a fast thermochemical reaction that requires fuel, oxygen, and a source of ignition, producing heat and light.

What is complete combustion?

Complete combustion occurs when fuels burn in excess oxygen, producing carbon dioxide and water.

What is incomplete combustion?

Incomplete combustion happens when there is a limited supply of oxygen, producing carbon monoxide or soot along with water.

What is oxidation?

Oxidation is a reaction involving the addition of oxygen or the removal of hydrogen, characteristic of combustion.

What is an exothermic reaction?

An exothermic reaction is one that releases heat, such as combustion.

What are hydrocarbons?

Hydrocarbons are organic compounds consisting of hydrogen and carbon, commonly used as fuels.

What are biofuels?

Biofuels are renewable fuels made from organic compounds, such as bioethanol and biodiesel.

What is a greenhouse gas?

Greenhouse gases are gases that absorb and emit radiation, contributing to the greenhouse effect and global warming.

What is carbon monoxide?

Carbon monoxide is a colorless, odorless toxic gas produced from incomplete combustion, which can bind to hemoglobin in blood.

What is transesterification?

Transesterification is a chemical process used to produce biodiesel from triglyceride oils and alcohol.

Chemical equation for incomplete combustion of propane

C3H8 + 5O2 → 3CO + 4H2O

Chemical equation for complete combustion of octane

2C8H18 + 25O2 → 16CO2 + 18H2O

Chemical equation for combustion of ethanol

C2H5OH + 3O2 → 2CO2 + 3H2O

Balanced equation for the combustion of butane

2C4H10 + 13O2 → 8CO2 + 10H2O

Chemical equation for the production of biodiesel from triglycerides

Triglyceride + Methanol → Glycerol + Biodiesel (Fatty Acid Methyl Esters)

Chemical equation for photosynthesis

6CO2 + 6H2O + light energy → C6H12O6 + 6O2

Chemical equation for respiration

C6H12O6 + 6O2 → 6CO2 + 6H2O + energy (ATP)

Chemical equation for the decomposition of hydrogen peroxide

2H2O2 → 2H2O + O2

Chemical equation for the reaction of carbon with oxygen

C + O2 → CO2

Chemical equation for the reaction of calcium carbonate with hydrochloric acid

CaCO3 + 2HCl → CaCl2 + H2O + CO2

What is the definition of kinetic energy?

Kinetic energy is the energy possessed by an object due to its motion, calculated as KE = 0.5mv².

What is the first law of thermodynamics?

The first law of thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another.

What is enthalpy?

Enthalpy is a thermodynamic quantity representing the total heat content of a system, often used in measuring heat exchange.

Define enthalpy of formation.

The enthalpy of formation is the change in enthalpy when one mole of a compound is formed from its elements in their standard states.

What is Hess's Law?

Hess's Law states that the total enthalpy change for a reaction is the sum of the enthalpy changes for individual steps, regardless of the pathway taken.

What is Gibbs free energy?

Gibbs free energy is a thermodynamic quantity that measures the maximum reversible work obtainable from a system at constant temperature and pressure.

What are catalysts?

Catalysts are substances that increase the rate of a chemical reaction without being consumed in the process.

Explain Le Chatelier's principle.

Le Chatelier's principle states that if a dynamic equilibrium is disturbed, the system will adjust to counteract the change and restore a new equilibrium.

What is the Arrhenius equation?

The Arrhenius equation relates the rate constant of a reaction to the temperature and activation energy, given by k = Ae^(-Ea/RT).

Define pH.

pH is a logarithmic scale that measures the acidity or alkalinity of a solution, with lower values indicating acidic and higher values indicating basic conditions.

What is a fuel cell?

A fuel cell is an electrochemical cell that converts chemical energy from a fuel into electricity through oxidation-reduction reactions.

What happens in a fuel cell?

In a fuel cell, hydrogen is oxidized, and oxygen is reduced, resulting in the generation of electricity, water, and heat.

What are the main components of a fuel cell?

The main components of a fuel cell are the anode, cathode, electrolyte, and external circuit for electricity flow.

What is the Nernst equation?

The Nernst equation calculates the cell potential of electrochemical cells, factoring in concentration and temperature.

What is electrolysis?

Electrolysis is a process that uses electrical energy to drive a non-spontaneous chemical reaction, commonly used to decompose compounds.

What is an oxidation reaction?

An oxidation reaction involves the loss of electrons by a substance, increasing its oxidation state.

What is a reduction reaction?

A reduction reaction involves the gain of electrons by a substance, decreasing its oxidation state.

What is the overall reaction in a hydrogen fuel cell?

The overall reaction in a hydrogen fuel cell is 2H2 + O2 → 2H2O, which produces electricity and water.

What is the significance of the standard reduction potential?

The standard reduction potential indicates the tendency of a species to gain electrons and be reduced; higher values mean greater tendency.

What is a redox reaction?

A redox reaction is a chemical reaction involving the transfer of electrons, where one species is oxidized and another is reduced.