An analytical chemist added some iron(II) carbonate powder to a boiling tube containing dilute hydrobromic acid. She observed fizzing and the formation of a pale green solution, Z.
Identify the gas that causes the fizzing and describe a test for it.
Gas: Test:
Solution Z contains bromide ions.
The student confirmed this by adding some silver nitrate solution. She observed a cream precipitate of silver bromide.
Give the formula of the cream precipitate, and name the other solution she should have added before the silver nitrate solution.
Formula of cream precipitate: Other solution:
Complete the word equation for the reaction in this test.
iron bromide+silver nitrate→silver bromide+————————————— \text{iron bromide} + \text{silver nitrate} \rightarrow \text{silver bromide} + \text{—————————————} iron bromide+silver nitrate→silver bromide+—————————————Solution Z contains metal ions. The student wanted to confirm whether the ions were Fe2+\text{Fe}^{2+}Fe2+ or Fe3+\text{Fe}^{3+}Fe3+.
What reagent should she add to decide whether solution Z contains Fe2+\text{Fe}^{2+}Fe2+ or Fe3+\text{Fe}^{3+}Fe3+ ions? State the result of the test in each case.
Reagent: Result with Fe2+\text{Fe}^{2+}Fe2+ ions: Result with Fe3+\text{Fe}^{3+}Fe3+ ions:
