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JEE Main202125 Feb 2021Morning ShiftChemistryThermodynamics (C)Actual

The reaction of cyanamide, NH 2 CN s with oxygen was run in a bomb calorimeter and ΔU was found to be - 742 . 24 kJ mol - 1 . The magnitude of ΔH 298 for the reaction NH 2 CN s + 3 2 O 2 g → N 2 g + O 2 g + H 2 O l is kJ . (Rounded off to the nearest integer) [Assume ideal gases and R = 8 . 314 J mol - 1 K - 1 ]

Correct answer

0

Step-by-step solution

ΔH = ΔU + Δn g RT = - 742 . 24 + 1 2 × 8 . 314 1000 × 298 = - 741   kJ / mol Hence answer is 741

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