Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Thermodynamics question

2008 · Q104
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /NEET
  3. /Chemistry
  4. /Thermodynamics
  5. /2008 · Q104

Thermodynamics question

2008 · Q104

NEETChemistryThermodynamicsMCQ+4 / −1
For the gas phase reaction,

PCl5(g)  ⇌\rightleftharpoons⇌ PCl3(g) + Cl2(g)

which of the following conditions are correct ?
  1. A
    Δ\DeltaΔH < 0 and Δ\DeltaΔS < 0
  2. B
    Δ\DeltaΔH > 0 and Δ\DeltaΔS < 0
  3. C
    Δ\DeltaΔH = 0 and Δ\DeltaΔS < 0
  4. D
    Δ\DeltaΔH > 0 and Δ\DeltaΔS > 0
View written solutionFree

Correct answer: D

Δ\Delta ΔH = Δ\Delta ΔE + Δ\Delta ΔngRT

Δ\Delta Δng = (1 + 1) – (1) = 1

⇒\Rightarrow⇒ Δ\Delta ΔH = Δ\Delta ΔE + RT

Thus, Δ\Delta ΔH is a positive quantity i.e., ∆H > 0. Now one mole of gaseous reactant dissociate into two moles of gaseous products thus, entropy increases i.e., Δ\Delta ΔS > 0.

PreviousNext

More from Thermodynamics

  • Which of the following are not state functions ? (I) q + w (II) q (III) w (IV) H − TS2008 · MCQ
  • Bond dissociation enthalpy of H2, Cl2 and HCl are 434, 242 and 431 kJ mol−1 respectively. Enthalpy of formation of HCl is2008 · MCQ
  • Consider the following reactions : (i) H+(aq) + OH−(aq) = H2O(l), ΔH = − X1 kJ mol−1 (ii) H2(g) + 1/2O2(g) = H2O(l), ΔH = − X2 kJ mol−1 (iii) CO2(g) + H2(g) = CO(g) + H2O(l), ΔH = − X3 kJ mol−1 (iv)…2007 · MCQ
  • Given that bond energies of H − H and Cl − Cl are 430 kJ mol−1 and 240 kJ mol−1 respectively and ΔHf for HCl is − 90 kJ mol−1, bond enthalpy of HCl is2007 · MCQ
  • Identify the correct statement for change of Gibb's energy for a system (ΔGsystem) at constant temperature and pressure.2006 · MCQ
  • The enthalpy and entropy change for the reaction: Br2(l) + Cl2(g) → 2BrCl(g) are 30 kJ mol−1 and 105 J K−1 mol−1 respectively. The temperature at which the reaction will be in equilibrium is2006 · MCQ
  • The enthalpy of hydrogenation of cyclohexene is is − 119.5 kJ mol−1. If resonance energy of benzene is − 150.4 kJ mol−1, its enthalpy of hydrogenation would be2006 · MCQ
  • Assume each reaction is carried out in an open container. For which reaction will ΔH = ΔE ?2006 · MCQ