Acids Bases And Salts

Step 1: Understand the litmus paper test and pH scale.
Litmus paper is a common indicator used to test the acidity or alkalinity of a solution.
Acids turn blue litmus paper red.
Bases (alkaline solutions) turn red litmus paper blue.
Neutral solutions do not change the color of either red or blue litmus paper. The pH scale ranges from 0 to 14:
pH 7 indicates an acidic solution.
pH = 7 indicates a neutral solution.
pH 7 indicates a basic (alkaline) solution. Step 2: Apply the litmus test result to determine the nature of the solution.
The problem states that "A Solution turns blue Litmus red". This indicates that the solution is acidic. Step 3: Use the pH scale to find a likely pH value for an acidic solution.
Since the solution is acidic, its pH must be less than 7. Step 4: Evaluate the given options.

(1) 11: This pH is greater than 7, indicating a basic solution. A basic solution would turn red litmus blue, not blue litmus red.
(2) 14: This pH is strongly basic. A strongly basic solution would turn red litmus blue.
(3) 5: This pH is less than 7, indicating an acidic solution. An acidic solution would turn blue litmus red. This is a likely pH.
(4) 10: This pH is greater than 7, indicating a basic solution. Step 5: Conclude the likely pH.
Based on the litmus test, the solution is acidic, and among the given options, pH 5 is the only value that corresponds to an acidic solution. (3) 5

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