Aman accidentally spilt vinegar on some pieces of an eggshell or marble and noticed bubbling. He then poured a soap solution on another piece of eggshell or marble, but no bubbles appeared. Why did bubbles occur with vinegar but not with soap solution?
Bubbles appeared with vinegar because vinegar is acidic in nature, and eggshells and marble contain calcium carbonate.
When an acid reacts with calcium carbonate, a chemical reaction occurs producing carbon dioxide gas, which appears as bubbles.
The reaction is: Acid + Calcium carbonate → Salt + Water + Carbon dioxide.
Soap solution is basic in nature and does not react with calcium carbonate, hence no bubbles are produced.
Bases do not chemically react with calcium carbonate in the same way acids do, so no gas is released.
Explanation
The chapter discusses neutralisation reactions between acids and bases. While the specific reaction between acids and calcium carbonate is not detailed in this chapter, the concept of acids reacting with substances is introduced. Vinegar contains acetic acid, which reacts with calcium carbonate (in eggshells and marble) to produce carbon dioxide gas. Soap solution, being basic, does not produce such a reaction with calcium carbonate.
Solution Steps
Vinegar is acidic in nature, while eggshells and marble contain calcium carbonate
Acids react with calcium carbonate to produce carbon dioxide gas, which appears as bubbles
The reaction produces salt, water, and carbon dioxide
Soap solution is basic in nature and does not react with calcium carbonate
Bases do not chemically react with calcium carbonate, so no gas is released