Inorganic Chemicals - Fundamentals of Industrial Chemistry: Pharmaceuticals, Polymers, and Business - page 14

intermediates. In water purification, chlorine can be directly added to water or
it can be reacted with sodium hydroxide to form sodium hypochlorite (bleach)
which can then be added to purify water. The use of chlorine to purify drink-
ing water is responsible for saving millions from death and sickness due to
water-borne diseases such as typhoid, cholera, dysentery, and gastro-enteritis.
Cl 2 + 2 NaOH NaClO + NaCl + H 2 O
Sodium hypochlorite
Sodium hydroxide has many applications in the chemicals industry and
is also used in the manufacture of soaps, detergents, textiles, and aluminum.
Often the demand of the caustic end-use markets varies from the demand
of the chlorine end-use markets. However, because they are coproduced, no
one makes caustic without making chlorine (or vice versa), even if they only
have orders for caustic. Because of these market fluctuations, the chloralkali
business necessitates a balance not required for other chemical manufacture.
To produce either caustic or chlorine, there needs to be an outlet for the other.
Chlorine is a severe eye, nose, throat, and upper respiratory tract irritant
and breathing high concentrations can be fatal [26]. At the Battle of Ypres,
Germany used chlorine as an asphyxiant against the French in World War I,
killing an estimated 800 [27]. Because of the problems inherent in shipping a
toxic compressible gas, much of the chlorine produced is produced captively.
Captive production means that a chemical is made for internal use and not for
transportation and sale. By manufacturing chlorine and then consuming it at
the same location, transportation risks can be avoided. Safety considerations
also dictate against the storage of large quantities of chlorine. Many of the
large chlorine producers use it directly to make chlorinated products such
as EDC.
QUESTIONS
1. A container of 25% oleum could be considered ________% sulfuric acid
(to nearest tenth of a percent).
2. Assuming 100% yield, a chloralkali plant that produces 320 tons of caustic
soda, also produces ________ tons of ________ (answer based upon the
larger volume chemical that is coproduced)
3. Which of the following is the largest use of sulfuric acid?
a. mining
b. waste water treatment