Question

\Lambdatomic hydrogen is obtained by passing ordinary hydrogen through (1) a suitable catalyst maintained at high temperature under high pressure (2) a solution containing zinc and sulphuric acid (3) an clectric arc (4) a silent clectric discharge at ordinary tempcrature

Short answer

Option (4) - a silent electric discharge at ordinary temperature.

Step-by-step solution

- Analyze the options

Carefully read each given method for obtaining atomic hydrogen: (1) using a suitable catalyst at high temperature and pressure, (2) using a solution with zinc and sulfuric acid, (3) using an electric arc, and (4) using a silent electric discharge at ordinary temperature.

- Understand atomic hydrogen production

Atomic hydrogen is highly reactive and usually produced by breaking the bonds of molecular hydrogen (H2) into individual hydrogen atoms (H). This process needs to overcome the strong H-H bond.

- Evaluate the methods

Evaluate each method in terms of feasibility for dissociating molecular hydrogen into atomic hydrogen. Methods (1) and (2) typically generate molecular hydrogen but do not sufficiently explain atomic hydrogen generation. Method (3) and (4) focus on disrupting the H-H bond more directly.

- Identify the correct method

Method (3) uses an electric arc, which generates high energy to break the H-H bonds. Method (4) involves a silent electric discharge at ordinary temperature, which effectively converts hydrogen molecules into atomic hydrogen by providing the required energy without involving high-temperature processes.

- Conclusion

The most suitable method for obtaining atomic hydrogen among the given options is using a silent electric discharge at ordinary temperature, i.e., option (4). This method directly provides the energy to break molecular hydrogen bonds without needing high temperature or pressure.

Key concepts

catalysis

Catalysis plays a crucial role in many chemical reactions by speeding up the process without being consumed by the reaction. For atomic hydrogen production, catalysis can be employed to facilitate the dissociation of molecular hydrogen (H2) into individual hydrogen atoms (H). However, in the context of our exercise, using a suitable catalyst at high temperature and pressure (option 1) is not the most efficient method for breaking the strong H-H bonds to produce atomic hydrogen. Catalysts typically work better with systems that operate under less extreme conditions and for reactions that do not require high energy inputs to break chemical bonds.

electric arc

An electric arc is a highly energetic process created by passing electricity through a gas, usually resulting in ionization. This method generates substantial heat and electrical energy, enough to dissociate molecular hydrogen (H2) into atomic hydrogen (H). The electric arc method (option 3 in the exercise) is effective because the intense energy supplied can break the strong bonds between the hydrogen molecules. However, this method also involves extremely high temperatures and can be less efficient compared to other methods that achieve the same result at lower energy costs.

silent electric discharge

A silent electric discharge is a method of applying electric energy to a gas without generating significant heat, hence the term 'silent.' In the context of atomic hydrogen production, a silent electric discharge at ordinary temperature (option 4 in the exercise) is highly effective. This method uses a specific setup to supply sufficient energy in the form of an electric field to break the strong H-H bonds in molecular hydrogen (H2) without applying high temperatures. This makes it more practical and energy-efficient for producing atomic hydrogen compared to the electric arc method.

molecular hydrogen dissociation

Molecular hydrogen dissociation involves breaking the H-H bonds in hydrogen molecules (H2) to produce two hydrogen atoms (H). This process requires a significant amount of energy due to the strength of the H-H bond, which is one of the strongest chemical bonds. Different methods can be used for molecular hydrogen dissociation, such as using catalysts, electric arcs, or silent electric discharges. Among these methods, the silent electric discharge is particularly advantageous for its ability to provide the necessary energy without high temperatures, making it a preferred method for industrial and laboratory applications seeking to produce atomic hydrogen efficiently.