UPSC Combined Geo-Scientist Main 2024 Chemistry Paper II PDF

Q1. Some useful fundamental constants and conversion factors

() N_A = 6.022 × 10²³ \text mol^-1

() Rydberg constant = 2.178 × 10^-18 \text J

() c = 2.998 × 10⁸ \text ms^-1

() k_B = 1.38 × 10^-23 \text JK^-1

() e = 1.602 × 10^-19 \text C

() m_e = 9.109 × 10^-31 \text kg

() F = 96485 \text C mol^-1

() R = 8.314 \text JK^-1 \text mol^-1

() h = 6.626 × 10^-34 \text Js

() π = 3.142

() 1 amu = 1.66 × 10^-27 \text kg

() 1 cal = 4.184 \text J

() 1 J = 1 \text kg m² \text s^-2

() 1 Å = 10^-8 \text cm = 10^-10 \text m = 0.1 \text nm = 100 \text pm

() 1 atm = 760 torr = 1.01325 × 10⁵ \text Pa

() 1 bar = 1 × 10⁵ \text Pa = 0.9869 \text atm

() 1 eV = 1.602 × 10^-19 \text J

() 1 L atm = 101.34 \text J

() 1 eV = 23060 \text cal/mol

() 4π^2c² = 3.55 × 10²² \text cm² \text s^-2

() (h²)/(8m_e) = 6.025 × 10^-38 \text J m²

() h_c = 1.986 × 10^-25 \text Jm

() (h)/(8π^2c) = 2.8 × 10^-44 \text kg m² \text cm^-1