BITSAT2023ChemistryThermodynamics (C)Actual
Given that bond energies of H - H and Cl - Cl are 430 ~kJ ~mol ⁻¹ and 240 ~kJ ~mol ⁻¹ respectively and H _ f for HCl is -90 ~kJ ~mol ⁻¹ , bond enthalpy of HCl is
Options
- A380 ~kJ ~mol ⁻¹
- B425 ~kJ ~mol ⁻¹
- C245 ~kJ ~mol ⁻¹
- D290 ~kJ ~mol ⁻¹
Correct answer
B. 425 ~kJ ~mol ⁻¹
Step-by-step solution
1 2 H ₂+ 1 2 Cl ₂ HCl aligned & H_ HCl = B.E. of reactant - B.E. of products &-90= 1 2 430+ 1 2 240- B.E. of HCl & B.E. of HCl =215+120+90=425 ~kJ ~mol ⁻¹ aligned