preparation of salts

Question

Atest can be done to show the presence of $$\mathrm{SO}_{4}{ }^{2-}(\mathrm{aq})$$ by adding acidified aqueous barium chloride or acidified aqueous barium nitrate．（i）State the observation that would show that $$\mathrm{SO}_{4}{ }^{2-}$$ is present．[1] （ii）Write an ionic equation for the reaction that occurs if $$\mathrm{SO}_{4}{ }^{2-}$$ is present．Include state symbols．

Answer 1

Answer:

（i）white precipitate （ii）$$\mathrm{Ba}^{2+}(\mathrm{aq})+\mathrm{SO}_{4}^{2-}(\mathrm{aq}) \rightarrow \mathrm{BaSO}_{4}(\mathrm{~s})$$ correct ionic equation（1） state symbols（1）

Explanation:

This question is about testing for the presence of sulfate ions ($$\mathrm{SO}_{4}^{2-}$$) in a solution using acidified barium chloride or barium nitrate.

Explanation:

(i) Observation: When barium chloride or barium nitrate is added to a solution containing sulfate ions, a white precipitate of barium sulfate ($$\mathrm{BaSO}_{4}$$) forms.

This is because barium sulfate is insoluble in water, and its formation indicates the presence of sulfate ions.

(ii) Ionic Equation: The reaction that occurs can be represented by the ionic equation:

$$
\mathrm{Ba}^{2+}(\mathrm{aq}) + \mathrm{SO}_{4}^{2-}(\mathrm{aq}) \rightarrow \mathrm{BaSO}_{4}(\mathrm{s})
$$

This equation shows that barium ions ($$\mathrm{Ba}^{2+}$$) from the barium chloride or barium nitrate react with sulfate ions ($$\mathrm{SO}_{4}^{2-}$$) to form the insoluble barium sulfate precipitate ($$\mathrm{BaSO}_{4}$$).

The state symbols indicate that barium ions and sulfate ions are in aqueous solution, while barium sulfate is a solid precipitate.