Which of the following species/reagent can reduce Fe3+(aq.) into Fe2+(aq.) at normal conditions? (NH4)2S, HI, Sn2+(aq.), CN-(aq.), NaNO2, SO2, Na2S2O3, SCN-(aq.), Acidified NaIO3

Question

Prashant Kotian · Accepted Answer

Correct answer: **5** / (NH4)2S + FE3+ -> FES↓ + S↓ + NH4+. HI + FE3+ -> FEI2 + I2. SN2+ + FE3+ -> FE2+ + SN4+. SO2 + FE3+ -> FE2+ + SO4^2-. S2O3^2- + FE3+ -> FE2+ + S4O6^2-.. Step 1: Identify the reactivity of the metal hydroxide. Copper(II) hydroxide, Cu(OH)2, is a basic hydroxide that is insoluble in water. Step 2: Observe the reaction with excess NaOH. Unlike amphoteric hydroxides (like Zn(OH)2 or Al(OH)3), copper(II) hydroxide is not amphoteric and does not dissolve in excess sodium hydroxide. Step 3: Consequently, the copper(II) hydroxide precipitate remains in the mixture, classifying the process as a precipitate formation reaction (type A). Thus, the correct option is (a).

💡 Solution & Explanation

Practice 22,000+ questions like this