Question

Which of the following is true when HCl (g) is passed through water? (i) It does not ionise in the solution as it is a covalent compound. (ii) It dissociates in the solution. (iii) It gives both hydrogen and hydroxyl ion in the solution. (iv) It forms hydronium ion in the solution due to the combination of hydrogen ion with water molecule. A) (i) only B) (iii) only C) (ii) and (iv) D) (iii) and (iv)​

Answer 1

Hydrochloric gas

Hydrogen is the first element in the periodic table it has a dual nature it is a alkaline metal as well as halogen non-metel . The position of hydrogen is a big subject of discussion the periods of elements are arranged according to their electronic configuration .

The the statement which is true about hydrogen chloride :

When HCL is passed through the water

1. If does not ionize in the solution as it is a covalent bond _ the statement is false because HCL has a property to ionize in the solution with water to form hydrochloric acid with chlorine.
2. It dissolves in the solution _ We have to use upward displacement because HCL is highly reactive and it reacts with water. we can say that a HCL dissociates in the solution.
3. It gives both hydrogen and hydroxyl ions in the solution_ The statement is false because there is no any hydroxylic creation .
4. It forms hydronium ions in the solution due to combination of hydrogen ions with water molecule - the statement is correct.

So the correct option will be tu 2,4 which is C .

Answer 2

When HCl is passed through water then it dissociates in the solution and forms hydronium ion in the solution due to the combination of the hydrogen ion with the water molecules. (OPTION D) as both (ii) and (iv) are the correct statements.

Explanation -

HYDROCHLORIC ACID -

• HCl is a strong inorganic acid that ionizes in water.
• It completely dissociates to form hydrogen and chloride ions.
• The chloride ion formed is the weak conjugate base.
• Hydrochloric acid is a good Lewis acid and acts as an electron donator.
• On dissolution of the acid in the water, it donates electrons to the water molecules.
• On combination, hydronium ions are formed that decrease the pH of the solution.
• The reaction involved is -

                    $HCl_(_a_q_) + H_2O_(_l_)$ → $H_3O^+_(_a_q_) + Cl^-_(_a_q_)$