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JEE Main202126 Feb 2021Evening ShiftChemistryThermodynamics (C)Actual

The average S - F bond energy in kJ mol - 1 of SF 6 is _. (Rounded off to the nearest integer) [Given : The values of standard enthalpy of formation of SF 6 g , S g and F g are - 1100 , 275 and 80 kJ mol - 1 respectively.]

Correct answer

0

Step-by-step solution

SF 6 g → S g + 6   F g If ∈ - bond enthalpy Δ r H = 6 × ϵ S - F = Δ f H S ,   g + 6 × Δ f H F ,   g - Δ f H SF 6 ,   g = 275 + 6 × 80 - - 1100 = 1855   kJ ϵ S - F = 1855 6 = 309 . 16   kJ   mol - 1

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