Question #a1805
1 Answer
Apr 10, 2014
Your premise is incorrect. Substitution and hydrogenation do not both involve the removal of hydrogen atoms from alkanes.
Substitution
Substitution in an alkane involves the removal of a hydrogen atom and its replacement with something else.
An example is the chlorination of methane.
H₃C-H + Cl-Cl → H₃C-Cl + H-Cl
Hydrogenation
Alkanes do not undergo hydrogenation. Hydrogenation is the addition of hydrogen to an alkene.
Hydrogenation does not remove H atoms from the alkene. Instead, it adds H atoms to the alkene.
An example is the hydrogenation of ethene.
H₂C=CH₂ + H-H → H-CH₂-CH₂-H
