Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 20154 April
Exam
JEE Main
Year
2015
Date
4 April
Subject
Chemistry
Chapter
Chemical Equilibrium

JEE Main 2015 · 4 April · Chemistry · Chemical Equilibrium

The standard Gibbs energy change at 300 K for the reaction 2A ⇌ B +...

The standard Gibbs energy change at 300 K for the reaction 2A⇌B+C2A ⇌ B + C is 2494.2 J. At a given time, the composition of the reaction mixture is \left[A\right] = \dfrac{1}{2}, \left[B\right] = 2 and \left[C\right] = \dfrac{1}{2}.Thereactionproceedsinthe:. The reaction proceeds in the:[ R = 8.314J / K - mol, e = 2.718 ]$ {Given antilog (-0.44)=0.36}

Options

  1. AReverse direction because Q<KCQ < {K}_{C}
  2. BForward direction because Q>KCQ > {K}_{C}
  3. CReverse direction because Q>KCQ > {K}_{C}
  4. DForward direction because Q<KCQ < {K}_{C}

Correct answer

C. Reverse direction because Q>KCQ > {K}_{C}

Step-by-step solution

ΔG∘=−RT ln KC\Delta {\text{G}}^{∘} = - {\text{RT ln K}}_{\text{C}}

2494.2=−8.314×300 ln KC\text{2494.2} = - \text{8.314} \times {\text{300 ln K}}_{\text{C}}

2494.2=−8.314×300×2.303 log KC\text{2494.2} = - \text{8.314} \times 300 \times {\text{2.303 log K}}_{\text{C}}

−2494.22.303×300×8.314=−0.44=log KC- \dfrac{\text{2494.2}}{\text{2.303} \times 300 \times \text{8.314}} = - \text{0.44} = {\text{log K}}_{\text{C}}

log KC=−0.44{\text{log K}}_{\text{C}} = - \text{0.44}

KC=0.36{\text{K}}_{\text{C}} = \text{0.36}

Q=[B][C][A]2=2×12(12)2=4\text{Q} = \dfrac{[ B ] [ C ]}{[ A{]}^{2}} = \dfrac{2 \times \dfrac{1}{2}}{{\left(\dfrac{1}{2}\right)}^{2}} = 4

Q>KC\text{Q} > {\text{K}}_{\text{C}}, reaction will shift in reverse direction.
Practice Chemical Equilibrium on Quantrex Academy →

More from Chemical Equilibrium

Consider the following reactions in which all the reactants and products are present in… JEE Main 2026Solid carbon, CaO and CaCO _3 are mixed and allowed to attain equilibrium at T K.… JEE Main 2026In a closed flask at 600 K, one mole of X _2 Y _4 (g) attains equilibrium as given below… JEE Main 2026One mole each of He and A(g) are taken in a 10 L closed flask and heated to 400 K to… JEE Main 2026The reaction A(g) leftharpoons B(g) + C(g) was initiated with the amount ' a ' of A(g) .… JEE Main 2026The values of pressure equilibrium constant recorded at different temperatures for the… JEE Main 2026For the following reaction at 50° C and at 2 atm pressure, 2N_2O_5(g) leftharpoons… JEE Main 2026At T(K) , the equilibrium constant of A_2(g) + B_2(g) leftharpoons C(g) is 2.7 × 10^ -5 .… JEE Main 2026 Full Chemical Equilibrium list All JEE Main PYQs