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| Uses of Hydrochloric Acid |
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| The main uses of the hydrochloric acid are mentioned below: |
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| 1) Hydrochloric acid is used in the production of dyes, drugs, paints, photographic chemicals etc. |
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| 2) It is used for the production of glucose from starch. |
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| 3) It is used for the extraction of glue from bones. |
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| 4) Hydrochloric acid helps in dissolving away calcium phosphate, in the extraction of bone charcoal. |
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| 5) A mixture of hydrochloric acid and sulphuric acid is used to dip the metals for cleaning metal surfaces before painting, electroplating, soldering, galvanizing etc. This process is called "pickling". |
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| 6) HCl acid is used in the preparation of chlorides. |
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| 7) It is used as a laboratory reagent. |
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| 8) Hydrochloric acid is used in the preparation of aqua-regia for dissolving metals like gold, platinum etc. These metals do not dissolve in any single acid, but readily dissolve in aqua-regia which is a mixture of acids. |
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| 9) It is produced in the digestive tract of man and animals and helps in the digestion of food. |
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| Aqua-regia |
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| This is a mixture of concentrated hydrochloric acid and concentrated nitric acid in the ratio 3:1 by volume. Aqua-regia means "royal water" (aqua = water, regia = royal). The two acids react to form nascent chlorine which reacts with the noble metals like gold, platinum etc. to form their respective chlorides. |
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| Uses of hydrochloric acid are summarized in figure 5.11 as shown below. |
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