Chemistry Adda Preparation of Acids class 10th

Preparation of Acids
Some acids can be prepared by the direct combination of a non-metal with hydrogen. For e.g.,







In the above reactions, the obtained gases like hydrogen chloride, hydrogen iodide and hydrogen sulphide are also called the acid anhydrides. They exhibit acidic properties, only when dissolved in water.Therefore an acid anhydride is a substance that dissolves in water to form an acid. In other words, it is the acid minus water (acid - water = acid anhydride).

Examples: CO2 gas is the acid anhydride of carbonic acid, SO3 gas is the acid anhydride of carbonic acid, HCl gas is the acid anhydride of hydrochloric acid.

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Preparation by Dissolving Acidic Oxide in Water


Oxides that can add on hydrogen ions to their molecules are called acidic oxides. Thus when they dissolve in water they associate with hydrogen ions to form acids.





Preparation by the Displacement of Metal Ions of Salts of Volatile Acids by Less Volatile Acid

The hydrogen ions of less volatile acids, like concentrated sulphuric acid, can help displace metal ions of salts of volatile acids, to produce the acid.






Preparation by the Action of Dilute Acids on Salts




Hydrogen sulphide is the acid anhydride.

Preparation by the Oxidation of Non-metals by Concentrated Nitric Acid

Non metals like sulphur, phosphorous get oxidized by concentrated nitric acid to form their respective acids.