Question

Choose the correct statement from the following:
(A). Water has highest density at 4°C
(B). Freezing point of water is 0°C
(C) An Ice cube does not completely dip in water, rather floats on water in a glass.
(D). Addition of common salt reduces freezing point of water.
Choose the correct answer from the options given below:

• A. (A), (B) and (D) only.
• B. (B), (C) and (D) only.
• C. (A), (B), (C) and (D).
• D. (A), (B) and (C) only.

Hint:

The anomalous expansion of water (highest density at 4°C) is a crucial concept. It explains why ice floats, which is essential for aquatic life to survive in frozen lakes during winter.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The question requires evaluating the validity of four common statements about the physical properties of water.
Step 2: Detailed Explanation:
- (A) Water has highest density at 4°C: This is a well-known anomalous property of water. As water cools, it becomes denser until it reaches 4°C, after which it starts to expand and become less dense. This statement is correct.
- (B) Freezing point of water is 0°C: By definition, at standard atmospheric pressure, the freezing point of pure water is 0 degrees Celsius (or 32 degrees Fahrenheit). This statement is correct.
- (C) An Ice cube ... floats on water in a glass: Ice is less dense than liquid water (due to the property described in A). According to Archimedes' principle, an object less dense than the fluid it is in will float. This statement is correct.
- (D) Addition of common salt reduces freezing point of water: This phenomenon is called freezing point depression. Dissolving a solute like salt (NaCl) in a solvent (water) lowers the temperature at which the solution freezes. This is why salt is used to de-ice roads. This statement is correct.
Step 3: Final Answer:
Since all four statements (A), (B), (C), and (D) are correct, the correct option includes all of them.