Chemistry 9701 · AS & A Level · Chemical energetics

Chemical energetics — practice question

In solid sulfur, the substance exists as molecules containing eight atoms joined by covalent bonds. For sulfur dioxide, the bonding arrangement is $\text{O}=\text{S}=\text{O}$. Enthalpy change of combustion of $\text{S}_8$, $\Delta H_c^\circ (\text{S}_8(s)) = -2376\,\text{kJ mol}^{-1}$. The energy needed to separate $1$ mole of $\text{S}_8(s)$ into gaseous atoms is $2232\,\text{kJ mol}^{-1}$. The $\text{O}=\text{O}$ bond enthalpy is $496\,\text{kJ mol}^{-1}$. Using these data, what is the value of the $\text{S}=\text{O}$ bond enthalpy?

  • A$239\,\text{kJ mol}^{-1}$
  • B$257\,\text{kJ mol}^{-1}$
  • C$319\,\text{kJ mol}^{-1}$
  • D$536\,\text{kJ mol}^{-1}$

Worked solution & mark scheme

This 1-mark question has a full step-by-step worked solution and mark scheme.

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI