| Hydrochloric acid is added dropwise to the aqueous solution of the unknown. Choose the concentration of HCl and how changes are to be observed. |
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Introductory investigations: The addition of acid |
| Hydrochloric acid is added dropwise to the aqueous solution of the unknown. Choose the concentration of HCl and how changes are to be observed. |
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| Consider if the change in pH is of a sufficient magnitude to support the view that a component with buffering properties is present. | ||||||
| Could anything be concluded about the buffering effect of the unknown? | ||||||
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| Consider possible components in the unknown. | ||||
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| Does the addition of 2 M HCl result in the formation of an acidic gas ? | ||||
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| Consider possible components in the unknown. | ||||
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By the dropwise addition of acid to an aqueous solution the resulting pH changes can indicate whether a buffering component is present or not. By the addition of acid to an aqueous solutionen it can be found whether an acidic gas can liberated or not. These methods are only relevant if the solution itself is not strongly acidic. |
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| A white precipitate of either barium carbonate or barium sulfite is formed. | ||||||||||||
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