During the manufacture of sparkler fireworks, a paste made from barium nitrate powder, aluminium powder, water and glue is spread onto wires and left to dry. At this point, the following exothermic reaction may take place. $16\text{Al} + 3\text{Ba(NO}_3)_2 + 36\text{H}_2\text{O} \rightarrow 3\text{Ba(OH)}_2 + 16\text{Al(OH)}_3 + 6\text{NH}_3$ Which conditions would be most suitable for slowing the rate of this reaction while the aluminium and barium nitrate remain unchanged?
- Atemperature $298\,\text{K}$, $\text{pH} = 7$
- Btemperature $298\,\text{K}$, $\text{pH} = 14$
- Ctemperature $398\,\text{K}$, $\text{pH} = 7$
- Dtemperature $398\,\text{K}$, $\text{pH} = 14$