Short answerEasy1 mark
3(i)
Alex was given a solution of an unknown salt Y for analysis. He performed the following tests and recorded his observations: To a part of the solution Y, he added silver nitrate solution and obtained a white precipitate which was soluble in ammonium hydroxide solution. To the remaining solution he added a few drops of sodium hydroxide solution and obtained a pale blue precipitate. Based on the observations made by Alex, identify:
the cation present in salt Y.
Topic: Qualitative analysis using NaOH and NH₄OH
Previous-year question practice database
Answer
Exam answer
Copper(II) ion, Cu²⁺.
Explanation
Cu²⁺ gives a pale blue Cu(OH)₂ precipitate with NaOH.
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