Q. Which gas is produced when dilute hydrochloric acid reacts with zinc?
✅ Correct Answer: (A)
Hydrogen
Explanation: Zinc reacts with dilute HCl in a single displacement reaction: Zn + 2HCl → ZnCl2 + H2. Hydrogen gas is liberated. Oxygen is not produced because this is not a decomposition or combustion reaction. Chlorine would require oxidation of chloride ions; instead chloride remains as Cl- in ZnCl2. Carbon dioxide is produced when carbonates react with acids, not metals reacting with acids.
Explanation by: Sikhar Chaudhary
Zinc reacts with dilute HCl in a single displacement reaction: Zn + 2HCl → ZnCl2 + H2. Hydrogen gas is liberated. Oxygen is not produced because this is not a decomposition or combustion reaction. Chlorine would require oxidation of chloride ions; instead chloride remains as Cl- in ZnCl2. Carbon dioxide is produced when carbonates react with acids, not metals reacting with acids.