It turns from reddish-brown to colourless (or decolourises).
A reaction in which two substances combine to form a single product.
Cracking.
C4H10.
Alcohol.
By cracking larger alkanes.
Solid catalyst (aluminium oxide).
The unknown compound is an alkane.
Their structural formulae.
Gas
At the third carbon of the pentane chain.
Butene (C4H8) and chlorine gas (Cl2).
They increase.
Phosphoric acid (H₃PO₄).
It increases.
C2H4 + Br2 → C2H4Br2.
Specific conditions.
The boiling point generally increases with the increasing number of carbon atoms.
Aqueous bromine.
Decolourises.
Cracking.
Methyl.
Alkenes.
Identify the branched chain.
Nickel catalyst.
Structural isomerism and stereoisomerism.
It increases.
Stereoisomerism occurs when compounds have the same molecular formula and connectivity but differ in the spatial arrangement of atoms.
Butane can have two structural isomers: n-butane and isobutane.
Cis isomers have substituents on the same side of the double bond, while trans isomers have substituents on opposite sides.
Reddish-brown.
A single product.
C2H4 + H2 → C2H6.
Hydration.
-7 °C
Isomerism is the phenomenon where compounds have the same molecular formula but different structural arrangements.
C4H8 + 6O2 → 4CO2 + 4H2O.
C₂H₄ + H₂O → C₂H₅OH.
Butane (C4H10) has two structural isomers: n-butane and isobutane.
High temperature.
Cracking.
C3H6 + C9H20.
They are in higher demand compared to longer chain alkanes.
As fuel or starting materials for the manufacture of ammonia.
Ethyl.
It has a carbon chain with branches.
300 °C.
C7H16.
C2H4 + 3O2 → 2CO2 + 2H2O.
No significant reaction occurs under normal conditions; alkanes are generally unreactive with bromine without the presence of UV light or heat.
C_nH_{2n}.
The reddish-brown bromine solution turns colourless.
Alkane and alkene.
As starting materials for making ethanol and plastics.
Their structural formulae.
Straight-chain alkane.
Identify the longest carbon chain.
Branched-chain alkane.
The double bond.
200 °C to 300 °C.
Structural isomerism occurs when compounds have the same molecular formula but differ in the connectivity of their atoms.
Dichlorobutane (C4H8Cl2).
Alkenes undergo addition reactions with bromine due to the presence of a double bond, resulting in decolourisation. Alkanes do not react with bromine under normal conditions because they only have single bonds.
Hydration of alkenes, forming alcohols.
Geometric (cis-trans) isomerism due to the presence of a double bond.
C12H26 → C5H10 + C7H16.
C4H10.
Compounds that have the same molecular formula but different structural formulae.
C4H10.
Propane.
The number must be as small as possible.
Alkenes contain at least one carbon-carbon double bond, while alkanes only have single bonds.
A minimum of two carbon atoms is needed to form a double bond (C=C).
Bromine is toxic and can be hazardous to handle, requiring careful safety precautions.
One carbon double bond (C=C).
Compounds that have the same molecular formula but different structural formulae.
C12H26.
-102 °C
Carbon dioxide gas and water vapor.
Structural isomerism and stereoisomerism.
60 atm (or 6000 kPa).
60 atm.
It increases.
Bromine adds across the double bond of the alkene, forming a dibrominated alkane. For example: C2H4 + Br2 → C2H4Br2.
Bromine is effective because it readily reacts with alkenes, causing a visible colour change, which is easy to observe.
Chlorine and bromine.
An alkene.
Alkenes and hydrogen.
Carbon atoms are joined up in a row.
Hydrogenation.
Addition reaction of alkenes.
2C3H6 + 9O2 → 6CO2 + 6H2O.
Structural isomerism occurs when compounds have the same molecular formula but different connectivity of atoms.
It acts as a catalyst in hydration reactions.
Alkenes, hydrogen (H2), and bromine (Br2).
Geometric isomerism (cis-trans isomerism).
Bromine provides a clear and immediate visual indication of the presence of alkenes through decolourisation.
Propyl.
Isomerism in alkanes refers to the existence of compounds with the same molecular formula but different structural arrangements.
30 °C
C4H8.
Stereoisomerism occurs when compounds have the same molecular formula and connectivity but differ in the spatial arrangement of atoms.
No, alkanes do not exhibit geometric isomerism due to the lack of double bonds.
A homologous series.
CnH2n, where n is the number of carbon atoms.
C2H4.
Ethene (C2H4).
Each alkene contains C=C.
By a CH2 unit.
At the C=C bond of ethene (unsaturated).
C3H6.
Propane (C3H8).
Conversion of alkenes to alkanes.
Halogenoalkanes.
C3H6.
The double bond (C=C).
C4H8.
C2H4 + Br2 → C2H4Br2.
C5H10.
-ene.
Unsaturated hydrocarbons.
Alkanes.
Hydrogenation.
Nickel catalyst and a temperature of 200 °C.
A group of organic compounds with the same functional group and similar chemical properties, differing by a constant unit.
Hydrogenation.
