This question requires use of the Data Booklet. A student combined $25\ \text{cm}^3$ of $0.10\ \text{mol dm}^{-3}$ sodium hydroxide solution with $25\ \text{cm}^3$ of $0.10\ \text{mol dm}^{-3}$ hydrochloric acid and observed a temperature increase of $2.5^\circ\text{C}$. Determine the enthalpy change for the reaction per mole of NaOH.
- A$-209\ \text{kJ mol}^{-1}$
- B$-104.5\ \text{kJ mol}^{-1}$
- C$-209\ \text{J mol}^{-1}$
- D$-522.5\ \text{J mol}^{-1}$