Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
AP EAMCET202120 Aug 2021Morning ShiftChemistryThermodynamics (C)Actual

At 60 ° C , dinitrogen tetroxide is fifty percent dissociated. Find its standard free energy change at this temperature and one atmosphere. [ Given: log 1 . 33 = 0 . 1239 ]

Options

  1. A  -650 J . mol   - 1
  2. B- 830   J . mol - 1
  3. C- 790   J . mol - 1
  4. D- 875   J · mol - 1

Correct answer

C. - 790   J . mol - 1

Step-by-step solution

The reaction showing the dissociation will be: N 2 O 4 ( s ) ⇌ 2 NO 2 ( g ) t = 0 1   mol 0   mol t = t eq 0 . 5   mol 1   mol Clearly, from this equation we can say that the total number of moles is 0 . 5 + 1 = 1 . 5   mol Hence, the partial pressure for the molecule will be P N 2 O 4   =   0 . 5 1 . 5 × 1 atm   =   1 3   atm P NO 2   =   1 1 . 5 × 1 atm   = 2 3   atm Now, according to the law of chemical equilibrium we know that

Practice Thermodynamics (C) on Quantrex Academy →

More from Thermodynamics (C)

Identify the INCORRECT statement 2026The standard enthalpies of formation of CH₄ (g), CO₂ (g) and H₂ O(l) are -74.8 kJ mol ⁻¹ , -393.5 kJ mol ⁻¹ and -285.8 kJ mol ⁻¹ respectively. Then the enthalpy change for the give 2026For an ideal gas undergoing an isothermal change, there is 2026Ozone is formed by the reaction O _ 2(g) + O _ (g) O _ 3(g) , H = -107.2 kJ . Given O=O bond energy is 498.0 kJ mol ⁻¹ , the average bond energy of ozone is: 2026H and S for a reaction are 35.5 kJ mol ⁻¹ and 83.6 J K ⁻¹ respectively. Assuming that H and S do not vary with temperature, the reaction is spontaneous when: 2026The heat of combustion of carbon to CO ₂ is -393.5 kJ mol ⁻¹ . The heat released on the formation of 35.2 g of CO ₂ by combustion of C is: 20265 moles of a gas is allowed to pass through a series of changes as shown in the graph, in a cyclic process. The processes C A , B C and A B respectively are 20251 mole of an ideal gas is allowed to expand isothermally and reversibly from 1 L to 5 L at 300 K. The change in enthalpy (in kJ ) is ( R =8.3 ~J ~K ⁻¹ ~mol ⁻¹ ) 2025 Full Thermodynamics (C) list All AP EAMCET PYQs