Question

A Solution reacts with egg-shell to give CO$_2$ gas, the Solution contains :

• A. Mg Cl$_2$
• B. Na Cl
• C. KCl
• D. HCl

Hint:

Remember that carbonates (like in egg-shells) react with acids to produce carbon dioxide gas. This is a common chemical test for both carbonates and acids.

Answer 1

The Correct Option is D

Step 1: Understand the composition of egg-shell.
Egg-shells are primarily composed of calcium carbonate (CaCO$_3$). Step 2: Recall the reaction of carbonates with acids.
Carbonates react with acids to produce carbon dioxide (CO$_2$) gas, water (H$_2$O), and a salt. This is a characteristic test for the presence of carbonates. Step 3: Analyze the given options.
(1) MgCl$_2$ (Magnesium Chloride): This is a salt and typically does not react with calcium carbonate to produce CO$_2$ gas.
(2) NaCl (Sodium Chloride): This is a salt and typically does not react with calcium carbonate to produce CO$_2$ gas.
(3) KCl (Potassium Chloride): This is a salt and typically does not react with calcium carbonate to produce CO$_2$ gas.
(4) HCl (Hydrochloric Acid): This is a strong acid. When HCl reacts with calcium carbonate, it produces calcium chloride (a salt), water, and carbon dioxide gas. Step 4: Write the chemical reaction.
CaCO$_3$(s) + 2HCl(aq) $\rightarrow$ CaCl$_2$(aq) + H$_2$O(l) + CO$_2$(g) Step 5: Conclude the correct solution.
Since the reaction with egg-shell (calcium carbonate) produces CO$_2$ gas, the solution must contain an acid. Among the given options, HCl is an acid. $$(4) HCl$$