Chemistry
The acid used in the laboratory preparation of carbon dioxide gas is:
- dil. hydrochloric acid
- conc. sulphuric acid
- dil. sulphuric acid
- conc. hydrochloric acid
Answer
dil. hydrochloric acid
Reason — The acid used in the laboratory preparation of carbon dioxide gas is dil. hydrochloric acid.
Conc. sulphuric acid forms a coating of calcium sulphate on the marble chips, stopping the reaction. Dil. sulphuric acid forms calcium sulphate (insoluble), which slows/stops the reaction. Conc. hydrochloric acid is too strong and not typically used in lab preparation; dilute acid is preferred for controlled reaction.