Explain conformations, reactivity and mechanism in ethane with all structures.

Ethane is the simplest hydrocarbon with a single carbon-carbon bond. It is a saturated hydrocarbon, meaning it has the maximum number of hydrogen atoms attached to each carbon atom.

1. Conformations of Ethane: The conformations of ethane refer to the different arrangements of the atoms that can be obtained by rotating the molecule around the carbon-carbon single bond. The two most important conformations are the staggered conformation and the eclipsed conformation.

• Staggered Conformation: In this conformation, the hydrogen atoms on the front carbon are as far away as possible from the hydrogen atoms on the back carbon. This is the most stable conformation of ethane because it minimizes the repulsion between the electron clouds of the hydrogen atoms.

• Eclipsed Conformation: In this conformation, the hydrogen atoms on the front carbon are directly in line with the hydrogen atoms on the back carbon. This is the least stable conformation of ethane because the electron clouds of the hydrogen atoms are very close to each other, leading to a high degree of repulsion.

2. Reactivity of Ethane: Ethane is relatively unreactive due to the strong carbon-carbon and carbon-hydrogen bonds. It does not react with many reagents at room temperature. However, it can undergo combustion in the presence of oxygen to produce carbon dioxide and water. It can also undergo halogenation in the presence of UV light or heat, where a hydrogen atom is replaced by a halogen atom.

3. Mechanism of Ethane Reactions: The mechanism of ethane reactions typically involves the breaking of a carbon-hydrogen bond and the formation of a new bond. For example, in the halogenation of ethane, the reaction proceeds via a radical mechanism. The halogen molecule is first dissociated into two radicals by UV light or heat. Then, one of these radicals collides with an ethane molecule and takes away a hydrogen atom to form a hydrogen halide, leaving behind an ethyl radical. This ethyl radical can then react with another halogen radical to form a halogenated ethane molecule.