JEE Main 2025 · ChemistryMultiple choiceSingle correctEasyApplication

JEE Main 3 April 2025, Shift 1, Chemistry Q55

Question 55 of 75 in this shift, Chemistry question 5 of 25, Section A.

In the following system,

\mathrm{PCl_5(g)} \rightleftharpoons \mathrm{PCl_3(g)} + \mathrm{Cl_2(g)}

at equilibrium, upon addition of xenon gas at constant T & p, the concentration of

(1) $\mathrm{PCl_3}$ will increaseOfficial answer
(2) $\mathrm{Cl_2}$ will decrease
(3) $\mathrm{PCl_5}$ will increase
(4) $\mathrm{PCl_5}$ , $\mathrm{PCl_3}$ & $\mathrm{Cl_2}$ remain constant

Official answer

Option 1

NTA final key.

Chapter: Equilibrium
Topic: Chemical Equilibrium
Idea tested: Inert Gas Effect at Constant Pressure

Same topic in other shifts

All Chemical Equilibrium questions

4 Apr 2026, Shift 1 · Q55At T(K), the equilibrium constant of $\mathrm{A_2}(g)+\mathrm{B_2}(g)\rightleftharpoons \mathrm{C}(g)$ is $2.7\times10^{-5}$ . What is the…EasySingle correct
5 Apr 2026, Shift 1 · Q74The values of pressure equilibrium constant recorded at different temperatures for the following equilibrium reaction have been given…MediumNumerical value
5 Apr 2026, Shift 2 · Q56The reaction $\mathrm{A(g)\rightleftharpoons B(g)+C(g)}$ was initiated with the amount 'a' of A(g). At equilibrium it is found that the…MediumSingle correct
6 Apr 2026, Shift 1 · Q57One mole each of He and A(g) are taken in a 10 L closed flask and heated to 400 K to establish the following equilibrium.…MediumSingle correct
6 Apr 2026, Shift 2 · Q74In a closed flask at 600 K, one mole of $\mathrm{X_2Y_4(g)}$ attains equilibrium as given below :…MediumNumerical value
8 Apr 2026, Shift 2 · Q55Consider the following reactions in which all the reactants and products are present in gaseous state $2\,xy \rightleftharpoons x_2 + y_2$ …MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.