Answer:
Step-by-step explanation:
Simple organic molecules having only carbon and hydrogen are alkanes, alkenes and alkynes.
Ways of making these molecules are referred to as synthesis
Synthesis of
(1) alkanes can be achieved by halogenation of an alkene or alkyne as shown in the reaction below
C₂H₄ + H₂ ⇒ C₂H₆
The reaction above shows an alkene (ethene) undergoing halogenation to form an alkane (ethane). This reaction occurs in the presence of a platinum or nickel catalyst
C₂H₂ + 2H₂ ⇒ C₂H₆
The reaction above shows an alkyne (ethyne) undergoing halogenation to form an alkane (ethane). This reaction also occurs in the presence of a nickel or platinum catalyst
(2) Alkanes can be achieved by Wurtz reaction; treating alkyl halides with sodium metal as shown below
CH₃CH₂Br + 2Na + BrCH₂CH₃ ⇒ CH₃CH₂CH₂CH₃ + 2NaBr
This reaction proceed in the presence of a dry ether.
(3) alkanes from Kolbe's electrolytic method; this involves the synthesis of alkanes through the electrolysis of sodium or potassium salt of a carboxylic acid
2CH₃COO⁻Na⁺ + 2H₂O ⇒ CH₃CH₃ + 2CO₂ + H₂ + 2NaOH
(4) alkenes from dehydration of alcohol, as shown in the reaction below
C₂H₅OH ⇒ C₂H₄ (-H₂O)
The reaction above proceeds by heating the alcohol (ethanol) at high temperature in the presence of strong acid such as sulphuric acid.