4.2 CYL - Chemistry (OpenStax)

Question

Diatomic chlorine and sodium hydroxide(lye) are commodity chemicals produced in large quantities, along with diatomic hydrogen via the electrolysis of brine according to the following unbalanced equation: 

\[NaCl\left( {aq} \right) + {H_2}O\left( l \right) \to NaOH\left( {aq} \right) + {H_2}\left( g \right) + C{l_2}\left( g \right).\]

Write balanced molecular, complete ionic, and net ionic equations for this process.

Step-by-Step Solution

Answer

The molecular reaction of the given process will be:

\[2NaCl\left( {aq} \right) + 2{H_2}O\left( l \right) \to 2NaOH\left( {aq} \right) + {H_2}\left( g \right) + C{l_2}\left( g \right).\]

The complete ionic reaction of the given process will be:

 

The net ionic reaction of the given process will be:

Determine the molecular reaction

Balance the given reaction.

\[2NaCl\left( {aq} \right) + 2{H_2}O\left( l \right) \to 2NaOH\left( {aq} \right) + {H_2}\left( g \right) + C{l_2}\left( g \right).\]

Determine the complete ionic reaction

Write the ionic form of the reaction in step 1.

\[2N{a^ + }\left( {aq} \right) + 2C{l^ - }\left( {aq} \right) + 2{H_2}O\left( l \right) \to 2N{a^ + }\left( {aq} \right) + 2O{H^ - }\left( {aq} \right) + {H_2}\left( g \right) + C{l_2}\left( g \right).\]

Determine the net ionic reaction

Write the net ionic equation by cancelling out the same ions.

\[2C{l^ - }\left( {aq} \right) + 2{H_2}O\left( l \right) \to 2O{H^ - }\left( {aq} \right) + {H_2}\left( g \right) + C{l_2}\left( g \right)\]