Question

Formation of H₂ gas by the action of dil. HCl and Zn pieces. 

(OR) 

What happens if dilute HCl is added to zinc granules. Explain the process with an experiment. What type of reaction is this? Write the balanced chemical equation for this process.

Answer 1

Formation of Hydrogen gas by action of dilute HCl on Zinc and testing of H₂ gas

Hydrogen gas experiment: 

1.  Take a few zinc granules in a conical flask. 
2.  Add about 5 ml of dilute hydrochloric acid to the conical flask. 
3.  Observe the changes in the conical flask. 
4.  Keep a burning matchstick near the mouth of the conical flask.
5.  The light of burning matchstick is put off with ‘pop’ sound. 
6.  This indicates the H₂ gas has released in this reaction. 
7.  When we touch the bottom of the conical flask with our finger, we feel hot. 
8.  So, this reaction produces heat. 
9.  It is a displacement reaction. Zn_(s) + 2HCl_(aq) → ZnCl_2(aq) + H_2(g)