What is C4H4? Important knowledge about C4H4.

1. Definition of C₄H₄
   C₄H₄ is a chemical formula corresponding to several different compounds, including butadiene, cyclobutene, and cyclobutadiene. However, it is most commonly referred to as butadiene.
   1.1 Names
   1.1.1 Common name: Butadiene
   1.1.2 English name: Butadiene
   1.2. Atomic mass: includes 4 Carbon atoms and 4 Hydrogen atoms.
   1.3. Atomic weight: 4(12.01) + 4(1.01) = 52.08 g/mol.
   1.3.1 Molecular structure: C₄H₄ has a chain structure, consisting of 4 Carbon atoms connected to each other, and each Carbon atom is connected to a Hydrogen atom.
   1.4 Ion structure: C₄H₄ does not form ions.

2. Characteristics: C₄H₄

2.1 Physical properties of C₄H₄
State: Gas
Color: Colorless
Odor: Odorless
pH: not applicable as it is a gas
2.2 Chemical properties of C₄H₄: C₄H₄ can react with O₂ to form CO₂ and H₂O. Besides, it can also participate in addition reactions due to the presence of pi bonds in its structure.

3. Common chemical equations of C₄H₄
   Specific example: C₄H₄ + 6O₂ -> 4CO₂ + 2H₂O

4. Synthesis of C₄H₄

4.1 Laboratory synthesis of C₄H₄: C₄H₄ is not typically synthesized in the lab due to its instability.
4.2 Industrial synthesis of C₄H₄: In industry, C₄H₄ is usually produced from the pyrolysis process of petroleum derivatives such as ethylene.