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UPSC Combined Geo-Scientist

Chemist

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

Mains Paper II covers physical chemistry.

UPSC Combined Geo-Scientist, Mains · 2024 · Mains Paper II

Q2. Boyle temperature of a van der Waals gas

Question

Define Boyle temperature (TB) of a non-ideal gas. Show that for a van der Waals gas, the Boyle temperature TB = a/Rb, where a and b are van der Waals constants.

Answer in brief

TB is the temperature at which [∂(PVm)/∂P]T = 0 as P → 0; for a van der Waals gas this slope is b − a/RT, so TB = a/Rb.

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Topic notes: real gases, the van der Waals equation, critical constants and Boyle temperature, with every Civil Services, IFoS and Geo-Scientist PYQ →

CoversBoyle temperaturevan der Waals equationTB = a/Rbsecond virial coefficientreal gases