Industrial Chemistry — Set 2

Correct Answer: D. CO and H2

Water gas is a mixture of carbon monoxide and hydrogen produced from steam and coke. It serves as a useful industrial fuel and a source of hydrogen gas. It is different from producer gas, which contains nitrogen.

Correct Answer: D. Tungsten

Tungsten is chosen because it has the highest melting point of all metals. This allows the filament to glow white-hot without melting during operation. It also has a low vapor pressure at high temperatures.

Correct Answer: C. Sodium thiosulfate

Sodium thiosulfate, known as 'hypo', dissolves unexposed silver halides from the film. This process makes the developed image permanent and light-insensitive. Modern digital photography has largely replaced this chemical method.

Correct Answer: D. Sulfuric acid

Sulfuric acid acts as the electrolyte that allows ions to flow between the plates. In a fully charged battery, the concentration of the acid is at its highest. These batteries are valued for their ability to provide high surge currents.

Correct Answer: C. Mercury

Cinnabar is a bright red mineral consisting of mercury(II) sulfide. Heating the ore in a current of air releases mercury vapor, which is then condensed. Mercury is the only metal that remains liquid at room temperature.

Correct Answer: A. Chlorine

Chlorine gas is released, which provides the bleaching and disinfecting action. Bleaching powder is chemically known as calcium oxychloride. It is widely used for water treatment and in the textile industry.

Correct Answer: C. Methane

Methane constitutes the largest portion of natural gas, often exceeding 90%. It is a clean-burning fossil fuel used for heating and electricity generation. Natural gas is often found trapped between rock layers deep underground.

Correct Answer: B. Galvanization

Galvanization creates a protective zinc coating that acts as a sacrificial anode. Even if the coating is scratched, the zinc corrodes instead of the iron. This method significantly extends the life of industrial steel structures.

Correct Answer: A. Graphite

Graphite is mixed with clay to create the core used for writing. Despite the name 'lead', pencils have not contained actual lead for centuries. Graphite is an allotrope of carbon with a slippery, layered structure.

Correct Answer: D. Ammonia

Ammonia is an efficient refrigerant due to its high latent heat of vaporization. It is preferred in industrial settings because it is cost-effective and environmentally friendly. However, it must be handled carefully due to its toxicity and odor.