Chlorine is manufactured by electrolysis of brine, or sodium chloride solution. Electrolysis uses direct current to drive an otherwise non-spontaneous reaction, usually to separate a compound into its elements. For example, electrolysis of water yields hydrogen gas and oxygen gas.
In the same way, NaCl is used to produce chlorine, in the form of chlorine gas. The cathode involved in electrolysis of brine can be represented by the following reaction:
`2H^+ + 2e^- -> H_2` ,...
Chlorine is manufactured by electrolysis of brine, or sodium chloride solution. Electrolysis uses direct current to drive an otherwise non-spontaneous reaction, usually to separate a compound into its elements. For example, electrolysis of water yields hydrogen gas and oxygen gas.
In the same way, NaCl is used to produce chlorine, in the form of chlorine gas. The cathode involved in electrolysis of brine can be represented by the following reaction:
`2H^+ + 2e^- -> H_2` , while the anode is `2Cl^-1 -> Cl_2 + 2e^-` , with the over-all reaction being:
`2NaCl + 2H_2O -> Cl_2 + H_2 + 2NaOH` . As you can see, sodium hydroxide is a by-product of this process.
Now, both hydrogen and chlorine here are produced as diatomic gases. The reason why this is the case is because, like any other elements that occur as diatomic molecules, this is the most stable state.
In the case of chlorine, it has a 7 valence electrons and only needs one more to attain the more stable octet valency. This is the reason why when it ionizes, it ionizes by taking another electron and has a net charge of -1. Another way to attain an octet valency, and hence stability, is to share its electron with another chlorine atom, and thus both of them will attain a stable octet valency. For this reason, it is diatomic.
As to why it is a gas, this has something to do with its boiling point. The boiling point of chlorine gas is -29.27F, which is way below room temperature, and the temperature at which is it produced. Boiling point is determined by various factors including molecular weight and intermolecular forces of attraction. As a diatomic molecule, chlorine is non-polar - the atoms involved in the bond are identical and hence share the electrons equally. Therefore, the only forces involved are London Dispersion Forces. LDFs are weak and hence, the boiling point is low. Because of this, it is produced as a gas.
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