Chlor Alkali Industries Questions and Answers

Answer: A

Current efficiency is by definition the fraction of the charge that produces the intended product. The missing five per cent goes into oxygen evolution and other side reactions. Cell design aims to keep the figure above ninety-five.

Answer: B

Correct answer: True

Electrolysis is the process, and it consumes roughly 2,000 to 3,000 kilowatt hours per tonne of chlorine - enough that electricity is the dominant cost of the product and that plants are sited where power is cheap and reliable. Brine purification, drying and caustic concentration all consume energy too, but together they are a fraction of the cell house load.

Answer: C

Correct answer: passing chlorine over slaked lime

Bleaching powder is made by absorbing chlorine into dry slaked lime, calcium hydroxide, giving a solid mixed calcium chloride hypochlorite. Its advantage over a hypochlorite solution is that it is a stable dry powder that can be transported and stored, which is why it remained the standard bleaching and disinfecting agent for so long.

Answer: D

The first two are correct and are the two main sources. The third is wrong, since electrolysis gives chlorine and hydrogen separately, which must then be combined to make the acid. By-product acid often carries organic impurities.

Answer: A

Mercury is toxic and persistent, and the losses were unacceptable once the effects became known. This drove the conversion of the industry to membrane cells over several decades. Amalgam decomposition released it into several streams.

Answer: B

Correct answer: tolerance of impurities in the brine

Impurity tolerance is the one respect in which the diaphragm cell is the better of the two: the membrane demands far purer brine, as this topic’s earlier items establish. The other three are all genuine membrane advantages - no asbestos to handle, caustic pure enough to need no salt removal, and the lowest energy consumption of the routes.