Question

A student took two tubes containing 2 mL of dilute hydrochloric acid and added zinc granules to test tube (A) and solid sodium carbonate to test tube (B) as shown below:
The correct observation would be
(1) Rapid reaction in both the test tubes
(2) Slow reaction in (A) and rapid reaction in (B)
(3) Rapid reaction in (A) but a slow reaction in (B)
(4) No reaction in any of the test tubes

Answer 1

rapid reaction in both test tubes

Answer 2

(1) Rapid reaction in both the test tubes is the correct observation.

• In test-tube A, zinc granules will react with dilute hydrochloric acid to form metallic salt and hydrogen gas.
• The chemical reaction is as follows- Zn + 2HCl --> ZnCl2 + H2.
• In test-tube B, sodium carbonate will react to form- Na2CO3 + 2HCl --> 2NaCl + H2O + CO2.
• In the above reactions, Zn represents zinc, HCl represents hydrochloric acid, ZnCl2 represents zinc chloride, H2 represents hydrogen gas, Na2CO3 represents sodium carbonate, H2O represents water and CO2 represents carbon dioxide.