Q1 · CSIR NET Chemistry, December 2013
Paper: CSIR NET December 2013 · Subject: Inorganic Chemistry · Chapter: Acid and Bases · Topic: Acid and Bases – General · Marks: 2 · Difficulty: Easy
Among the following, the correct acid strength trend is represented by
(a)$[\mathrm{Al}(\mathrm{H}_2\mathrm{O})_6]^{+3}<[\mathrm{Fe}(\mathrm{H}_2\mathrm{O})_6]^{+3}<[\mathrm{Fe}(\mathrm{H}_2\mathrm{O})_6]^{+2}$
(b)$[\mathrm{Fe}(\mathrm{H}_2\mathrm{O})_6]^{+3}<[\mathrm{Al}(\mathrm{H}_2\mathrm{O})_6]^{+3}<[\mathrm{Fe}(\mathrm{H}_2\mathrm{O})_6]^{+2}$
(c)$[\mathrm{Fe}(\mathrm{H}_2\mathrm{O})_6]^{+2}<[\mathrm{Fe}(\mathrm{H}_2\mathrm{O})_6]^{+3}<[\mathrm{Al}(\mathrm{H}_2\mathrm{O})_6]^{+3}$
(d)$[\mathrm{Fe}(\mathrm{H}_2\mathrm{O})_6]^{+2}<[\mathrm{Al}(\mathrm{H}_2\mathrm{O})_6]^{+3}<[\mathrm{Fe}(\mathrm{H}_2\mathrm{O})_6]^{+3}$
Answer
Answer (as printed): D
Explanation
For aqua ion complex , acidity is more when (i) small size (ii) greater charge. CSIR JUNE 15
Explanation as extracted from the printed page; notation may be imperfect.
Study loop for Acid and Bases