Question

The carbon dioxide produced in water gas shift reaction is removed by scrubbing with:
A) Sodium hydroxide solution
B) Sodium arsenite solution
C) Sodium chloride solution
D) Water

Answer 1

Hint: A contaminant that is present in the product carbon dioxide which is produced in water gas shift reaction is removed by the scrubbing process. The scrubbing material is used as the catalyst in the reaction and one can analyze and select the correct catalyst.

Complete step by step answer:
1) First of all we will learn about the process where the reaction is generally known as water gas shift reaction. In this reaction there is a redox type of reaction mechanism involved in the formation of carbon dioxide from the water gas.
2) This reaction involves a considerable change of the oxidation state of the initial and final state of the catalytic metal. The sodium arsenite solution is used as a catalyst in this reaction. In the solution of sodium arsenite, the element arsenic is undergone through the regenerative change in the oxidation state of the initial and final state.
3) While undergoing this reaction there are two different mechanisms used where in the first mechanism the water molecule is firstly activated by the abstraction of hydrogen from the water molecule and then there is the dissociation of the resulting hydroxide ion from the atomic oxygen.
4) The formed carbon monoxide is then oxidized in presence of atomic oxygen which will then form the molecule of carbon monoxide.
5) In the second type of mechanism the carbon monoxide formed is directly oxidized by the hydroxide ion which will form a carboxyl intermediate and then it will undergo the dissociation of the carboxyl group. In the last step, the hydrogen atom is recombined to form the hydrogen gas and carbon dioxide molecule.

Therefore, the carbon dioxide produced in the water gas shift reaction is removed by scrubbing with Sodium arsenite solution which shows the option B as the correct choice.

Note:
The water gas shift reaction is a very unique process that is used for the removal of contaminants present in the gases. The sodium arsenite is used as an antiseptic, herbicides, and insecticide widely. Sodium arsenite is also used for the making of dyes.