Heat evolved in the reaction H2 + Cl2 → 2HCl is 182 kJ. Bond energies of H - H and Cl - Cl are 430 and 242 kJ/mol-1 respectively. The H - Cl bond energy is

Question

Heat evolved in the reaction H2 + Cl2 → 2HCl is 182 kJ. Bond energies of H - H and Cl - Cl are 430 and 242 kJ/mol-1 respectively. The H - Cl bond energy is (A) 245 kJ mol-1 (B) 427 kJ mol-1 (C) 336 kJ mol-1 (D) 154 kJ mol-1

Tardigrade Admin · Accepted Answer

Δ H=-2×εH-Cl+εH-H+εCl-C ∴ 182=-2× a+430+242 ∴ a=245 kJ mol -1

Q. Heat evolved in the reaction $H_{2} + C l_{2} \to 2 H Cl$ is $182 k J$ . Bond energies of $H - H$ and $Cl - Cl$ are $430$ and $242 k J / m o l^{- 1}$ respectively. The $H - Cl$ bond energy is

$245 k J m o l^{- 1}$

$427 k J m o l^{- 1}$

$336 k J m o l^{- 1}$

$154 k J m o l^{- 1}$

$Δ H = - 2 \times ε_{H - Cl} + ε_{H - H} + ε_{Cl - C}$
$∴ 182 = - 2 \times a + 430 + 242$
$∴ a = 245 k J m o l^{- 1}$

Q. Heat evolved in the reaction H2​+Cl2​→2HCl is 182kJ. Bond energies of H−H and Cl−Cl are 430 and 242kJ/mol−1 respectively. The H−Cl bond energy is

245kJmol−1

427kJmol−1

336kJmol−1

154kJmol−1