Process: 1 Weigh solid sodium bicarbonate and sodium carbonate with equal mass, and put them in two identical uninflated balloons respectively.
2 Take two clean test tubes and add equal volumes of hydrochloric acid respectively.
3 Put two balloons on the mouth of the test tube (the belly of the balloon must lean against the edge of the test tube to prevent hydrochloric acid from reacting with the solids in the balloon, and at the same time, tighten the mouth of the balloon to prevent air leakage during the test and affect the results).
4. Align the two inclined balloons so that hydrochloric acid can react with these two solids at the same time.
5 Observe the expansion of two balloons and compare the reaction rates of sodium bicarbonate and sodium carbonate with hydrochloric acid.
Objective: Let students solve some simple problems with simple methods through experiments.
Basis: The reaction speed of sodium bicarbonate and hydrochloric acid is much faster than that of sodium carbonate. So the phenomenon is obvious and can be distinguished by the size of the balloon.
Conclusion: The reaction rate of sodium bicarbonate with hydrochloric acid is faster than that of sodium carbonate.