Verified Solution • 2025–26 Session moderate

QJEEM20Ph5e4b: JEE Main 2020 Physics - Class 11 JEEM20Ph5e4b Solution: Initially a gas of diatomic molecules is contained in a…

Initially a gas of diatomic molecules is contained in a cylinder of volume V1 at a pressure P1 and temperature 250 K. Assuming that 25% of the molecules get dissociated causing a change in number of moles. The pressure of the resulting gas at temperature 2000 K, when contained in a volume 2V1 is given by P2 . The ratio P2P1{{{P_2}} \over {{P_1}}} is ________.

Step-by-Step Verified Solution

We know, PV = nRT
∴\therefore P1V1 = nR (250)

and P2(2V1) = 5n4R×(2000){{5n} \over 4}R \times \left( {2000} \right)

By Dividing

P12P2{{{P_1}} \over {2{P_2}}} = 4×2505×2000{{4 \times 250} \over {5 \times 2000}}

⇒\Rightarrow P1P2=15{{{P_1}} \over {{P_2}}} = {1 \over 5}

⇒\Rightarrow P2P1=5{{{P_2}} \over {{P_1}}} = 5

Related Learning Resources & Exam Preparation