Question

Take a small piece of magnesium in a test tube. Add a few drops of dilute
hydrochloric acid in it. Chemical reaction takes place. You can see bubbles of a
gas rising up
Identify the gas formed here
171
SCERT
General Education Department
Samagra Shlksha, Kerala
Class :8
Activity Card
Touch the bottom of the test tube. It is found to be hot. Give reason,
Which type of chemical reaction does this belong to?
(Thermochemical reaction/photochemical reaction/electrochemical reaction)​

Answer 1

Answer:

This is intended as a class practical. It is best if the students work in pairs because setting up and starting the experiment requires more than one pair of hands. One student can add the magnesium ribbon to the acid and stopper the flask, while the other starts the stopclock. During the experiment, one student can take the readings while the other records them. The experiment itself takes only a few minutes. But allow at least 30 minutes to give students time to set up, take readings and draw graph.

Hydrogen gas (extremely flammable) is generated in the experiment. Students should not have access to any source of ignition.