Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JIPMER2016ChemistrySolid State

If oxide ions are arranged in hcp and the aluminium ions occupy two thirds of octahedral voids. What will be the formula of the compound?

Options

  1. AAlO ₃
  2. BAl ₂ O ₃
  3. C( Al ₂ O ₃ )₂
  4. DAl ₃ O ₄

Correct answer

B. Al ₂ O ₃

Step-by-step solution

In hcp arrangement of oxide ion. Number of octabedral (oh) voids for each oxide ion =1 Number of tetrahedral ( Td ) voids for each oxide ion =2 Al ³⁺ occupies only 2 / 3 of octahedral voids. Thus, number of Al ³⁺ for each oxide ion =2 / 3 Ratio of oxide ion : Aluminium ion 3: 2 Thus, formula is Al ₂ O ₃ .

Practice Solid State on Quantrex Academy →

More from Solid State

Which of the following formulae is used to find total volume of atoms present in face-centred cubic unit cell? 2026What is the packing efficiency of a metal crystal if it crystallizes in a face centered cubic lattice ? 2026What is the total number of tetrahedral voids present in a single fcc unit cell? 2026The unit cell of metal contains four particles. Calculate the volume of the unit cell if the molar mass of metal is 192 g mol ⁻¹ . [ N_A = 1.5 10²⁵ g cm ⁻³ mol ⁻¹ ] 2026A metal forms fcc unit cell with unit edge length 400 pm . Calculate the number of atoms present in 0.6 g of metal if the density of metal is 12.0 g/cm ^3 2026A compound is formed by two elements X and Y. The atoms of element Y form a hcp structure. The atoms of element X occupy 1/3 of octahedral voids. What is the formula of a compound? 2026An element has bcc structure with atomic radius 200 pm. Find the volume of unit cell. 2026Which of the following crystal system has four types of unit cells? 2026 Full Solid State list All JIPMER PYQs