Organic Chemistry: Hydrocarbons and Alkanes

The study of carbon-containing compounds.

A compound made only of carbon and hydrogen.

Fuel formed from ancient plants and animals.

A hydrocarbon with only single bonds.

A compound with only single bonds between atoms.

A series of compounds with similar properties & structure, differing by CH2.

Compounds with the same molecular formula but different structures.

CnH2n+2

A measure of a fuel's resistance to knocking (exploding prematurely) in an engine. Higher octane numbers indicate better performance.

The process of rearranging the atoms within a molecule to create a different structural isomer. This changes the molecule's properties, like octane number.

Breaking down large hydrocarbon molecules (like long chains) into smaller, more useful molecules using heat and catalysts. This increases the yield of valuable products like gasoline.

A process that uses catalysts to create ring-shaped molecules from straight-chain hydrocarbons. This involves removing hydrogen atoms and forming a ring structure.

Oxygen-containing compounds added to fuels to increase octane number and reduce harmful emissions like carbon monoxide.

A set of rules for naming organic compounds, developed by the International Union of Pure and Applied Chemistry.

A side chain attached to a main carbon chain in an alkane. Examples include methyl (CH3), ethyl (C2H5), etc.

Used to indicate two identical groups attached to a main carbon chain.

The longest continuous chain of carbon atoms in a molecule.

A hydrocarbon with only single bonds between carbon atoms.

Molecules with the same molecular formula but different arrangements of atoms.

Alkenes are soluble in non-polar solvents, meaning they dissolve in liquids like oil.

Burning ethyne produces a bright, smoky flame and significant soot due to its high carbon-to-hydrogen ratio.

The reddish-brown bromine water decolourises when reacted with an unsaturated compound, indicating the presence of double or triple bonds.

Aliphatic compounds consist of open chains of carbon atoms or closed chains (rings) that behave similarly to open chains.

A six-carbon ring with alternating double and single bonds, resulting in a highly stable and delocalised electron system.

No, benzene is an unsaturated compound with alternating double bonds but its delocalised electrons make it very stable and unreactive.

A process that separates crude oil into different fractions based on their boiling points, resulting in a range of useful products.

In fractional distillation, smaller molecules with lower boiling points condense and are collected higher up the column where it is cooler.

Refinery gases, like methane, ethane, propane, and butane, are used as fuel within the refinery itself.

The study of heat changes that occur during chemical reactions.

The amount of heat released or absorbed during a chemical reaction. A negative ΔH indicates heat is released (exothermic), while a positive ΔH indicates heat is absorbed (endothermic).

The heat released when one mole of a substance is burned completely in excess oxygen.

A device used to measure the heat of combustion accurately.

The amount of heat energy produced when 1 kg of fuel is completely burned in oxygen.

The average energy required to break one mole of a specific covalent bond.

The heat change when one mole of H+ ions reacts with one mole of OH- ions.

Exothermic reactions release heat, making the surroundings warmer. Endothermic reactions absorb heat, making the surroundings cooler.

They have the same molecular formula but different arrangements of atoms. Think of rearranging building blocks to make different shapes.

Propane has a lower boiling point because it's smaller with fewer intermolecular forces. Think of smaller magnets holding less strongly.

C4H10 + 13/2 O2 → 4CO2 + 5H2O

The change in enthalpy, a measure of heat released or absorbed during a reaction.

Subtract the sum of the enthalpies of formation of reactants from the sum of the enthalpies of formation of products.

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

When you reverse a reaction, the enthalpy change flips its sign.