When coke (carbon) reacts with salt (sodium chloride), it undergoes a process called the carbothermal reduction or the Deacon process. This reaction occurs at high temperatures, typically above 900 degrees Celsius.

The overall reaction can be represented as:

2NaCl(s) + C(s) -> 2Na(s) + Cl2(g) + CO(g)

In this reaction:

1. Carbon (C) acts as a reducing agent and takes oxygen from sodium chloride (NaCl) to form carbon monoxide (CO).

2. Sodium chloride (NaCl) undergoes decomposition, where the sodium (Na) atoms lose their valence electron to form neutral sodium atoms, while the chlorine (Cl) atoms gain electrons to form chlorine gas (Cl2).

The sodium atoms produced in the reaction can vaporize at high temperatures and rise upwards. These vapors can be condensed and collected as metallic sodium. The chlorine gas (Cl2) produced is a valuable industrial chemical used in various processes, such as water treatment, bleaching, and the production of PVC (polyvinyl chloride).

It's important to note that this reaction is typically carried out in an industrial setting under controlled conditions due to the high temperatures required and the toxic nature of the chlorine gas produced.