Question

Temperature of maximum density of H$_2$O is y K and D$_2$O is x K. (x - y) (in K) is nearly

• A. 7.0
• B. 3.5
• C. 4.0
• D. 8.5

Hint:

Remember the anomalous behavior of water: its maximum density occurs at 4$^\circ$C, not at its freezing point. Heavy water (D$_2$O) behaves similarly, but its temperature of maximum density is higher, at about 11.2$^\circ$C.

Answer 1

The Correct Option is A

This question concerns the anomalous expansion of water (H$_2$O) and heavy water (D$_2$O).
The temperature at which normal water (H$_2$O) exhibits its maximum density is approximately 4$^\circ$C.
The question provides the variable y for this temperature in Kelvin.
y = $4 + 273.15 = 277.15$ K.
Heavy water (D$_2$O) also shows a similar property, but its maximum density occurs at a different temperature.
The temperature of maximum density for heavy water is approximately 11.2$^\circ$C.
The variable x represents this temperature in Kelvin.
x = $11.2 + 273.15 = 284.35$ K.
We are asked to find the difference (x - y).
x - y = $284.35 \text{ K} - 277.15 \text{ K} = 7.2$ K.
This calculated value of 7.2 K is approximately equal to 7.0 K.