Textbook Problem

On Easter Sunday, April 3, 1983, nitric acid spilled from a tank car near downtown Denver, Colorado. The spill was neutralized with sodium carbonate:

$2{\text{HNO}}_3\left(aq\right)+{\text{Na}}_2{\text{CO}}_3\left(aq\right)\to 2{\text{NaNO}}_3\left(aq\right)+{\text{H}}_2\text{O}\left(l\right)+{\text{CO}}_2\left(g\right)$

a. Calculate ∆H° for this reaction. Approximately 2.0 ×10⁴ gal nitric acid was spilled. Assume that the acid was an aqueous solution containing 70.0% HNO₃ by mass with a density of 1.42 glcm3. What mass of sodium carbonate was required for complete neutralization of the spill, and what quantity of heat was evolved? ( $\Delta H_f^{°}$ for NaNO₃(aq) = −467 kJ/mol)

b. According to The Denver Post for April 4, 1983, authorities feared that dangerous air pollution might occur during the neutralization. Considering the magnitude of ∆H°, what was their major concern?