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Q109
(CAPF/2026)
Science & Technology › Basic Science (Physics, Chemistry, Biology)
Which one of the following processes is not used for the production of hydrogen gas?
Result
Your answer:
—
·
Correct:
D
Explanation
The hydrolysis of calcium carbide does not produce hydrogen gas; instead, it produces acetylene (C2H2) gas. The chemical reaction is: CaC2 + 2H2O → Ca(OH)2 + C2H2. This process was historically used in carbide lamps and for oxy-acetylene welding.
The other options are valid methods for hydrogen production:
- Electrolytic process: Electrolysis of acidified or alkaline water decomposes H2O into hydrogen and oxygen.
- Water gas-steam process: Also known as the Bosch process, it involves reacting water gas (CO + H2) with steam over a catalyst (Fe2O3) to produce more H2.
- Liquefaction of coal gas: Coal gas contains roughly 50% hydrogen. Since hydrogen has a much lower boiling point than other constituents like methane or carbon monoxide, it can be isolated by cooling the mixture until the other gases liquefy.
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