Paper: CSIR-NET June 2019 · Subject: Inorganic Chemistry · Chapter: Main Group Elements · Topic: Main Group Elements – General · Marks: 2 · Difficulty: Medium
The species that results by replacing one quarter of $\mathrm{Si}(\mathrm{IV})$ in pyrophyllite $\left[\mathrm{Al}_{2}(\mathrm{OH})_{2} \mathrm{Si}_{4} \mathrm{O}_{10}\right]$ with Al(III) [charge balance by K(1)] is
(a)muscovile
(b)-4, +5
(c)montmorillonite
(d)tale
Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
Replacing one quarter of the tetrahedral Si by Al in pyrophyllite and balancing with interlayer K⁺ gives muscovite mica, KAl₂(OH)₂(AlSi₃O₁₀).