Activity . CAUTION : This activity needs the teacher’s assistance. n Set the apparatus as shown in Fig. .
. n Take about mL of dilute sulphuric acid in a test tube and add a few pieces of zinc granules to it. n What do you observe on the surface of zinc granules? n Pass the gas being evolved through the soap solution.
n Why are bubbles formed in the soap solution? n Take a burning candle near a gas filled bubble. n What do you observe? n Repeat this Activity with some more acids like HCl, HNO and CH COOH.
n Are the observations in all the cases the same or different? Figure . Figure . Figure .
Figure . Figure . Reaction of zinc granules with dilute sulphuric acid and testing hydrogen gas by burning Note that the metal in the above reactions displaces hydrogen atoms from the acids as hydrogen gas and forms a compound called a salt. Thus, the reaction of a metal with an acid can be summarised as – Acid + Metal → Salt + Hydrogen gas Can you now write the equations for the reactions you have observed?