Question

Given that $\Delta H_f\left(H\right)=218kJ/mol$, express the $H-H$ bond energy in $kcal/mol$:

• A. $52.15$
• B. $911$
• C. $109$
• D. $52153$

Answer 1

Answer: (C)

$109$

$H-H⟶H+H;\Delta H$

$\Delta H$ is the bond energy

Therefore, $2\Delta H={\Delta }_{f}H$

$\therefore \Delta H=\frac{{\Delta }_f\left(H\right)}{2}$

$=\frac{218}{2}KJ/mol$

$\Delta H=109KJ/mol$