Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NTA Abhyas 2020
Exam
NTA Abhyas
Year
2020
Subject
Chemistry
Chapter
Chemical Equilibrium

NTA Abhyas 2020 · Chemistry · Chemical Equilibrium

Ammonium sulphide and ammonium selenide on heating dissociates as...

Ammonium sulphide and ammonium selenide on heating dissociates as (NH_{4})_{2}S(s) ⇌2NH3(g)+H2S(g);Kp1=9×10−3atm3(NH4)2Se(s)⇌ 2NH_{3}(g)+ H_{2}S(g); K_{p1}=9 × 10^{-3} atm^{3} (NH_{4})_{2}Se(s)⇌2NH3(g)+H2Se(g);Kp2=4.5×10−3atm3Thetotalpressureoverthesolidmixtureatequilibriumis2NH_{3}(g) + H_{2}Se(g); K_{p2}=4.5 × 10^{-3} atm^{3} The total pressure over the solid mixture at equilibrium is

Options

  1. A0.15 atm
  2. B0.3 atm
  3. C0.45 atm
  4. D0.6 atm

Correct answer

C. 0.45 atm

Step-by-step solution

\begin{array}{ll}{\left({\text{NH}_{4}\right)}_{2} \text{S}\left(\text{s}\right) ⇌ {\text{2NH}_{3} \left(\text{g}\right) + {H}_{2} \text{S}\left(\text{g}\right) \\ \text{2p}\text{p}\end{array}

\begin{array}{ll}{\left({\text{NH}_{4}\right)}_{2} \text{Se}\left(\text{s}\right) ⇌ {\text{2NH}_{3} \left(\text{g}\right) + {H}_{2} \text{Se}\left(\text{g}\right) \\ \text{2q}\text{q}\end{array}

Kp1=(pNH3)2⋅pH2S=(2p+2q)2⋅p=9.0×10−3{K}_{\text{p} 1} = {\left({p}_{\text{NH} 3}\right)}^{2} \cdot {p}_{{H}_{2} \text{S}} = {\left(2 \text{p} + 2 \text{q}\right)}^{2} \cdot \text{p} = \text{9.0} \times {10}^{- 3}

Kp2=(pNH3)2⋅pH2Se=(2p+2q)2⋅q=4.5×10−3{K}_{\text{p} \text{2}} = {\left({p}_{\text{NH} 3}\right)}^{2} \cdot {p}_{{H}_{2} \text{S} \text{e}} = {\left(2 \text{p} + 2 \text{q}\right)}^{2} \cdot \text{q} = \text{4.5} \times {10}^{- 3}

∴pq=2⇒p=2q∴ \dfrac{\text{p}}{\text{q}} = 2 ⇒ \text{p} = 2 \text{q}

∴Kp1=(2p+p)2⋅p=9.0×10−3∴ {K}_{\text{p} 1} = {\left(\text{2p} + \text{p}\right)}^{2} \cdot \text{p} = \text{9.0} \times {10}^{- 3}

∴p=0.1atmandq=0.12=0.05∴ \text{p} = \text{0.1} \text{atm} \text{and} \text{q} = \dfrac{\text{0.1}}{2} = \text{0.05}

Total pressure = 2p + 2q + p + q = 3p + 3q

& & & & & & & & & & & & = 3 × 0.1 + 3 × 0.05 = 0.45 atm
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 NTA Abhyas JEE Main PYQs