Identifying the Chemical Transformation Type

The question asks us to identify the type of chemical reaction represented by the conversion of H2C = CH - CH2CH3 to H3CCH = CHCH3.

Let's look at the chemical structures involved:

• Reactant: H₂C = CH - CH₂CH₃. This molecule is But-1-ene. It is an alkene with the double bond located between the first and second carbon atoms.
• Product: H₃CCH = CHCH₃. This molecule is But-2-ene. It is also an alkene, but the double bond is located between the second and third carbon atoms.

Now, let's consider the molecular formulas of these two compounds:

• But-1-ene: C₄H₈
• But-2-ene: C₄H₈

Both But-1-ene and But-2-ene have the same molecular formula (C₄H₈) but different structural formulas due to the different position of the double bond. Molecules with the same molecular formula but different structural formulas are called isomers.

Understanding Isomerization Reaction

An isomerization reaction is a process in which a molecule is transformed into another molecule that has the same atoms but different structural arrangement. In simpler terms, it's a reaction where one isomer is converted into another isomer.

Analyzing the Given Transformation

The reaction shows the conversion of But-1-ene to But-2-ene. Since But-1-ene and But-2-ene are isomers of each other, the transformation from one to the other is an isomerization reaction.

Let's briefly consider why the other options do not fit this transformation:

• Substitution: This type of reaction involves replacing one atom or group with another. The given reaction does not involve any replacement of atoms or groups.
• Elimination: This type of reaction involves removing atoms or groups from a molecule, often leading to the formation of a double or triple bond. While the molecules involved are alkenes, the reaction doesn't involve the removal of atoms; it's a rearrangement of the double bond position.

Therefore, based on the definition of isomers and the transformation shown, the reaction type is isomerization.