Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main202118 Mar 2021Morning ShiftChemistryThermodynamics (C)Actual

For the reaction C 2 H 6 → C 2 H 4 + H 2 the reaction enthalpy ∆ r H in kJmol - 1 is (Round off to the Nearest Integer). [Given : Bond enthalpies in kJmol - 1 : C - C : 347 , C = C : 611 ; C - H : 414 , H - H : 436 ]

Correct answer

0

Step-by-step solution

Δ r H = ϵ C - C + 2 ϵ C - H - ϵ C = C + ϵ H - H = [ 347 + 2 × 414 ] - [ 611 + 436 ] = 128

Practice Thermodynamics (C) on Quantrex Academy →

More from Thermodynamics (C)

An ideal gas ( 0.5 mol), initially at 2 bar pressure, is compressed at a constant temperature of 600 K in two steps: first, against a constant external pressure of P bar ( 2 < P < 2026List-I contains various physical/chemical processes, and List-II contains combinations of changes in enthalpy ( H ) and entropy ( S ). Match each entry in List-I to the appropriate 2026Consider the reaction 2 H ₂ S (g) + 3 O ₂(g) 2 H ₂ O (l) + 2 SO ₂(g) The magnitude of enthalpy change for the reaction in kJ mol ⁻¹ is ________. (Nearest integer) Given: _fH^ ( H ₂ 2026Match List - I with List - II. Given V₁ and V₂ are initial and final volumes respectively. List - I (Isothermal process) List - II (Expression) A. Reversible expansion I. q = 0 B. 2026Arrange the following isothermal processes in order of the magnitude of the work ( p - V ) involved between states 1 and 2 . A. Expansion in single stage w_A B. Expansion in multi 2026Consider the reaction X Y at 300 K. If H^ and K are 28.40 kJ mol ⁻¹ and 1.8 10⁻⁷ at the same temperature, then the magnitude of S^ for the reaction in J K ⁻¹ mol ⁻¹ is _______. (Ne 2026Consider the following data for the reaction X₂(g) + Y₂(g) 2XY(g) at 600 K . The _r G^ (in kJ mol ⁻¹ ) for the reaction is : Compound _f H^ _ 600K (kJ mol ⁻¹ ) S^ _ 600K (J mol ⁻¹ 2026The correct order of molar heat capacities measured at 298 K and 1 bar is : 2026 Full Thermodynamics (C) list All JEE Main PYQs