JEE Main 2022 · 27 Jul · Shift 1 · Chemistry Q84

← JEE Main 2022 · 27 Jul · Shift 1

ChemistryInteger+4 / -1Question 84 of 90

The molar heat capacity for an ideal gas at constant pressure is 20.785 J K $^{-1}$ mol $^{-1}$ . The change in internal energy is 5000 J upon heating it from 300 K to 500 K. The number of moles of the gas at constant volume is ______. [Nearest integer] (Given: R = 8.314 J K $^{-1}$ mol $^{-1}$ )

Your answer

Answer and worked solution

Official answer: 2

$C_V=C_P-R$ $=12.471$ J K $^{-1}$ mol $^{-1}$ ( $\frac32R$ ).

Moles. $n=\frac{5000}{12.471\times200}=2.0$ .

Answer: 2

Topics:First law and enthalpy

← Previous question Next question →

JEE Main 2022 · 27 Jul · Shift 1, Chemistry question 84