The industrial preparation of hydrogen gas from water gas is referred to as

Analysis

The question asks for the specific industrial process used to produce hydrogen gas from "water gas" (a mixture of carbon(II) oxide and hydrogen).

Concept Explanation

To understand this, we must look at the two-stage production of hydrogen from coal:

1. Water Gas Production: Steam is passed over red-hot coke to produce water gas: $C(s) + H_2O(g) \rightarrow CO(g) + H_2(g)$
2. Hydrogen Enrichment (The Bosch Process): The carbon(II) oxide ($CO$) in the water gas is reacted with more steam in the presence of a catalyst (iron(III) oxide) at high temperatures. This converts the $CO$ into $CO_2$, which is then removed, leaving behind a higher concentration of hydrogen gas: $CO(g) + H_2O(g) \rightleftharpoons CO_2(g) + H_2(g)$

This second stage, where $CO$ is converted to $CO_2$ to increase the yield of hydrogen, is known as the Bosch process.

Evaluation of Options

• A. Bosch process: This is the correct industrial method for obtaining hydrogen from water gas.
• B. Contact process: This is the industrial method for the manufacture of sulphuric acid.
• C. Haber process: This is the industrial method for the manufacture of ammonia.
• D. Bayer process: This is the industrial method for the extraction of alumina (aluminium oxide) from bauxite ore.

Conclusion

The industrial preparation of hydrogen gas from water gas is the Bosch process.

Exam Tip

To avoid confusion in the exam hall, remember these "Industrial Process" pairings:

• Haber = Ammonia ($NH_3$)
• Contact = Sulphuric Acid ($H_2SO_4$)
• Bosch = Hydrogen ($H_2$)
• Bayer = Aluminium ($Al$)