Correct Option
The correct option is 1, 2, 3 and 4
Explanation
Acids and bases are chemical substances found in nature and many household products. Bases are bitter in taste, soapy to touch, and turn red litmus blue. Identifying the specific chemical nature of common substances is fundamental to understanding their applications in daily life.
Statement-wise Analysis
- Pair 1 is Correct: Lime water is a saturated solution of Calcium hydroxide ($Ca(OH)_2$). It is commonly used to test for the presence of carbon dioxide, which turns the solution milky.
- Pair 2 is Correct: Soap is prepared through the process of saponification, which involves heating fats or oils with a strong base. Sodium hydroxide ($NaOH$) is typically used for making hard soaps, while Potassium hydroxide ($KOH$) is used for soft soaps.
- Pair 3 is Correct: Milk of Magnesia is a suspension of Magnesium hydroxide ($Mg(OH)_2$). It acts as a mild base and is widely used as an antacid to neutralize excess stomach acid and relieve indigestion.
- Pair 4 is Correct: Window cleaners often contain Ammonium hydroxide ($NH_4OH$). Ammonia is effective at cutting through grease and evaporates quickly without leaving streaks, making it suitable for glass cleaning.
Key Takeaway
Common household bases include Calcium hydroxide (Lime water), Sodium hydroxide (Soap), Magnesium hydroxide (Milk of Magnesia/Antacids), and Ammonium hydroxide (Window cleaners).