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UPSC Combined Geo-Scientist

Chemist

  • 3 descriptive papers
  • 200 marks each
  • 3 h per paper

Mains Paper III covers analytical and organic chemistry.

UPSC Combined Geo-Scientist, Mains · 2017 · Mains Paper III

Q2(d). Orthorhombic unit cell

Question

For an orthorhombic mineral, λ=1.54 Å and (100), (010), (001) occur at 2θ=22.5°,9.8°,28.8°. Find cell dimensions and formula units per cell, with M=140 and density 4.2 g cm⁻³.

Answer in brief

a=3.947 Å, b=9.015 Å, c=3.096 Å; Z≈2.

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CoversOrthorhombic unit cellX-ray diffraction

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