Alkalis

Alkalis produce solutions in the pH range 7-14. They can be used by farmers to neutralise acid soil or they can be used to convert fats and oils into soap.

Acids and alkalis react together to produce salt and water. For example, hydrochloric acid reacts with sodium hydroxide to produce sodium chloride and water.

hydrochloric acid + sodium hydroxide -> sodium chloride + water

During the LeBlanc process, that was used to make the alkali sodium carbonate, the poisonous gases hydrogen chloride and hydrogen sulfide were produced.