In Table 12.4 are listed the inorganic chemicals from the Chemical and Engineering top 50 list in terms of total tonnage. For each one of them that you can, give a likely important industrial use and list another chemical that could best substitute for that chemical should it, for some reason, be unavailable.
$$
\begin{aligned}
&\text { Table 12.4 Inorganic Chemicals among the Top } 50 \text { in U.S. Production in } 1984\\
&\begin{array}{clc}
\hline \text { Rank } & \text { Chemical Substance } & \text { Production (millions of tons } \\
\hline 1 & \text { Sulfuric acid } & 79.37 \\
2 & \text { Nitrogen } & 43.41 \\
3 & \text { Ammonia } & 32.41 \\
4 & \text { Calcium oxide (lime) } & 32.20 \\
6 & \text { Oxygen } & 31.04 \\
7 & \text { Sodium hydroxide } & 22.45 \\
8 & \text { Phosphoric acid } & 22.22 \\
9 & \text { Chlorine } & 21.45 \\
10 & \text { Sodium carbonate } & 17.02 \\
11 & \text { Nitric acid } & 16.08 \\
13 & \text { Urea } & 14.30 \\
14 & \text { Ammonium nitrate } & 14.01 \\
19 & \text { Carbon dioxide } & 7.80 \\
25 & \text { Hydrochloric acid } & 5.72 \\
30 & \text { Ammonium sulfate } & 4.13 \\
31 & \text { Potassium carbonate } & 3.53 \\
33 & \text { Carbon black } & 2.89 \\
38 & \text { Aluminum sulfate } & 2.16 \\
40 & \text { Calcium chloride } & 2.10 \\
44 & \text { Sodium sulfate } & 1.74 \\
45 & \text { Titanium dioxide } & 1.60 \\
46 & \text { Sodium silicate } & 1.50 \\
49 & \text { Sodium tripolyphosphate } & 1.33 \\
& \text { Total inorganics } & 366.15 \\
& \text { Trand total } & 180.39 \\
\hline
\end{array}
\end{aligned}
$$
(In some cases you may decide that the properties of a given compound are so unique that it will be irreplaceable; if so, justify this conclusion.)