Chapter 7, Problem 80E

Calculate ∆Hº for each of the following reactions using the data in Appendix 4:

$\begin{array}{ll}4\text{Na}\left(s\right)+{\text{O}}_2\left(g\right)\hfill & \to 2{\text{Na}}_2\text{O}\left(s\right)\hfill \\ 2\text{Na}\left(s\right)+2{\text{H}}_2\text{O}\left(l\right)\hfill & \to 2\text{NaOH}\left(aq\right)+{\text{H}}_2\left(g\right)\hfill \\ 2\text{Na}\left(s\right)+{\text{CO}}_2\left(g\right)\hfill & \to {\text{Na}}_{\text{2}}\text{O}\left(s\right)+\text{CO}\left(g\right)\hfill \end{array}$

Explain why a water or carbon dioxide fire extinguisher might not be effective in putting out a sodium fire.