The ferrous ion in a given sample is detected by the formation of a white precipitate on the additio — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Adding potassium ferrocyanide, K4[Fe(CN)6], to a solution of iron(II) (ferrous) ions in the absence of air produces a white precipitate. Step 2: This precipitate is potassium iron(II) hexacyanoferrate(II), which has the chemical formula K2Fe[Fe(CN)6]. Step 3: This formula matches option (a).