Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main
Exam
JEE Main
Subject
Chemistry
Chapter
p Block Elements (Group 13 & 14)

JEE Main · Chemistry · p Block Elements (Group 13 & 14)

Aqueous ammonia is used as a precipitating reagent for Al 3 + ions...

Aqueous ammonia is used as a precipitating reagent for Al3+ ions as Al(OH)3 rather than aqueous NaOH, because

Options

  1. ANH4+{NH}_{4}^{+} is a weak base
  2. BNaOH\text{NaOH} is a very strong base
  3. CNaOH\text{NaOH} forms [Al(OH)4]−{{\text{[Al(OH)}}_{4} \text{]}}^{−} ions
  4. DNaOH\text{NaOH} forms [Al(OH)2]+{{\text{[Al(OH)}}_{2} \text{]}}^{+} ions.

Correct answer

C. NaOH\text{NaOH} forms [Al(OH)4]−{{\text{[Al(OH)}}_{4} \text{]}}^{−} ions

Step-by-step solution

Al(OH)3 formed with NaOH dissolves in excess of NaOH to form aluminate ion.
which is stable.

AlCl3+3NaOH⟶2Al(OH)3↓+3NaCl{AlCl}_{3} + 3 \text{NaOH} ⟶ 2 \text{Al} {\left(\text{OH}\right)}_{3} ↓ + 3 \text{NaCl}

Al(OH)3+OH−→[Al(OH)4]−Soluble\begin{array}{ll}\text{Al}\left(\text{OH}\right) \text{3} + {OH}^{−} \to \left[\text{Al}{\left(\text{OH}\right)}_{4}\right] - \\ \text{Soluble}\end{array}
Practice p Block Elements (Group 13 & 14) on Quantrex Academy →

More from p Block Elements (Group 13 & 14)

Given below are two statements : Statement I: Aluminium upon reaction with NaOH forms… JEE Main 2026Consider the following reactions Na_ 2 ~B_ 4 O_ 7 Δ 2 X+ Y CuSO_ 4 + Y Non-Luminous flame… JEE Main 2026It is noticed that Pb^ 2+ is more stable than Pb^ 4+ but Sn^ 2+ is less stable than Sn^… JEE Main 2026The correct statements from the following are : A. Ionic radii of trivalent cations of… JEE Main 2026Given below are two statements : Statement I : Elements ' X ' and ' Y ' are the most and… JEE Main 2026Consider the following reactions. PbCl_ 2 +K_ 2 CrO_ 4 arrow ~A+2 KCl (Hot solution)… JEE Main 2026Given below are two statements : Statement I : The number of pairs among [SiO_ 2 , CO_ 2… JEE Main 2026The group 14 elements A and B have the first ionisation enthalpy values of 708 and 715… JEE Main 2025 Full p Block Elements (Group 13 & 14) list All 99 Percentile Qs Bank for JEE Main PYQs