Which of the following is used for softening hard water?
A. Bleaching powder
B. Baking soda
C. Plaster of Paris
D. Washing soda
Answer: Option D
Solution (By JKExamLibrary)
Washing soda (sodium carbonate, Na₂CO₃) is used to remove permanent hardness of water. It reacts with soluble calcium and magnesium chlorides/sulfates to form insoluble carbonates, which can be filtered out. Baking soda, bleaching powder, and plaster of Paris do not have this water-softening capability.
Explanation:
Chlorophyll, the green pigment in plants, contains a magnesium ion (Mg²⁺) at the center of the porphyrin ring. It's essential for photosynthesis. Haemoglobin in blood contains iron. Calcium is in bones. Sodium is in body fluids.
Explanation:
Ionic compounds consist of oppositely charged ions held together by strong electrostatic forces (ionic bonds). This results in high melting points and solubility in polar solvents.
No comments yet. Be the first to start the discussion!