Organic Chemistry: Alkanes and Fossil Fuels

A series of compounds with similar chemical properties & gradually changing physical properties. Members differ by a CH2 unit.

Compounds with the same molecular formula but different structural formulas. Different arrangements.

Side chains in alkanes, named as CH3-methyl, C3H7-ethyl.

IUPAC rules for naming organic compounds. Lowest numbers for substituents.

Naming of alkanes based on longest chain length, substituent position and type.

Contains one or more double or triple bonds between atoms.

Homologous series of hydrocarbons with a carbon-carbon double bond.

CnH2n, general formula describing the alkene series.

Liquefied Petroleum Gas, a mixture of propane and butane that is easily liquefied under pressure.

Sulfur compounds added to LPG to give it a strong, unpleasant smell, acting as a warning for leaks.

A measure of a fuel's resistance to knocking or premature ignition in an engine.

Premature ignition of the fuel-air mixture in an engine before the spark plug ignites it, resulting in a loud knocking sound.

The spontaneous ignition of a fuel-air mixture due to high temperature and pressure, without a spark.

The length and branching of the hydrocarbon chains affect the octane number.

Lead was previously added to petrol to reduce knocking, but it was found to be harmful to health.

The less volatile fractions remaining after more volatile components are removed from crude oil.

A chemical test used to identify the presence of alkenes. Bromine water, initially red-brown in colour, becomes colourless upon reaction with an alkene.

A chemical test used to identify the presence of alkenes and alkynes. The purple solution of potassium permanganate (KMnO4) turns colourless upon reaction with an unsaturated compound.

An organic compound containing a benzene ring structure.

A six-carbon ring structure with alternating single and double bonds. It is a highly stable and aromatic compound.

The sharing of electrons between multiple atoms in a molecule.

A process used to separate crude oil into different fractions, based on their boiling points.

Gases produced during the fractional distillation of crude oil, mainly methane, ethane, propane, and butane.

A thick, black liquid mixture of hydrocarbons found underground, requiring refinement to produce useful products.

The amount of heat released when one mole of acid reacts completely with one mole of base.

A reaction that releases heat to the surroundings, causing the temperature of the system to increase.

The amount of heat required to raise the temperature of 1 kg of a substance by 1 Kelvin (or 1 degree Celsius).

Use the formula: Heat Liberated = Mass x Specific Heat Capacity x Temperature Change (Q = mcΔT).

The difference between the final temperature and the initial temperature of the system.

The process of converting straight-chain alkanes into their isomers using heat and a catalyst. This process changes the arrangement of atoms within the molecule, resulting in branched isomers.

Breaking down long-chain hydrocarbons into shorter chains using heat and catalysts. This process increases the production of smaller molecules that are in higher demand.

A process that uses catalysts to form ring compounds (cyclic hydrocarbons) from straight-chain alkanes. This process involves the loss of hydrogen gas.

Oxygen-containing compounds added to fuel to increase its octane number and make it burn cleaner, reducing carbon monoxide emissions.

A method for producing hydrogen gas by reacting methane (natural gas) with steam in the presence of a catalyst. This process releases hydrogen and carbon monoxide.

Producing hydrogen gas by applying electricity to water. This method involves splitting water into hydrogen and oxygen.

The total enthalpy change for a reaction is the same whether the reaction occurs in one step or in a series of steps.

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

The most stable form of an element or compound at 298 K (25 °C) and 1 atm.

Heat liberated = mass x specific heat capacity x temperature rise.

By adding the enthalpy changes of individual steps, we can find the overall enthalpy change for the reaction.

Hess's Law can be used to calculate the heat of formation of a compound indirectly by combining known enthalpy changes of other reactions.

Because the reaction is exothermic, meaning that heat is released into the surroundings.