Chemistry - Salt Analysis Question with Solution | TestHub
ChemistrySalt AnalysisTEST OF CATIONS, Group 3, 4, 5, 6, 0Medium2 minQB
ChemistryMediumsingle choice
An element ' M ' forms insoluble hydroxide, which is soluble in both excess of NaOH and excess of solution, element ' M ' is
Options:
Answer:
C
Solution:
The element 'M' forms an insoluble hydroxide that is amphoteric, meaning it reacts with both strong bases (like NaOH) and some acids (or complexing agents like NH₃). Zinc hydroxide, Zn(OH)₂, fits this description.
1. Zn(OH)₂ (s) + 2NaOH (aq) Na₂[Zn(OH)₄] (aq) (soluble complex)
2. Zn(OH)₂ (s) + 4NH₃ (aq) [Zn(NH₃)₄](OH)₂ (aq) (soluble complex)
Aluminum hydroxide (Al(OH)₃) is soluble in excess NaOH but not in excess NH₃. Lead(II) hydroxide (Pb(OH)₂) is soluble in excess NaOH but only slightly in excess NH₃. Iron(III) hydroxide (Fe(OH)₃) is insoluble in both. Therefore, 'M' is Zinc (Zn).
Stream:JEESubject:ChemistryTopic:Salt AnalysisSubtopic:TEST OF CATIONS, Group 3, 4, 5, 6, 0
⏱ 2mℹ️ Source: QB
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