Question

Heavy water is not used for drinking because:
A. it is poisonous
B. it is costly
C. its physiological action is different from ordinary water
D. its chemical properties are different from ordinary water

Answer 1

Let us understand what heavy water is. We have to remember that the heavy water has the molecular formula ${D_2}O$ and is a water that contains only deuterium rather than the common hydrogen-1 isotope that makes up most of the hydrogen in ordinary water.Hence,heavy water is also known scientifically as deuterium dioxide.

Complete step by step answer:
We must remember that the deuterium is one of two stable isotopes of hydrogen.It has a mass approximately twice that of the usual isotope. We have to remember that the Deuterium is also represented as "heavy hydrogen" because of the extra neutron in the atomic nucleus. As we know that the hydrogen atom present in ordinary water has a single proton in its nucleus.
One method to obtain heavy water $\left( {{D_2}O} \right)$ is electrolysis of water to produce hydrogen and oxygen that contains normal gas along with deuterium. Hydrogen is then liquified and distilled and deuterium is allowed to react with oxygen to produce heavy water.
Heavy water is not radioactive and not harmful if ingested by human beings in small quantities
The difference in atomic masses owes to the difference in chemical properties between heavy and ordinary water.
The solvent properties of heavy water are different from that of normal water which can affect biological systems.
Heavy water is used as a moderator of neutrons in nuclear power plants in certain types of nuclear reactors.
In the laboratories,heavy water is used in studies of metabolic study of physiological and biochemical processes as an isotopic tracer.
Although heavy water is associated with nuclear reactors and radioactive materials,pure heavy water is not radioactive if consumed by human beings in small quantities.However, if taken for a long duration of time,poisoning may occur. Hence,it is not liable to say that heavy water cannot be consumed due to its poisonous nature.
Therefore, the option A can be regarded as incorrect.
The production process of heavy water is a costly matter. Although it cannot be the sole reason to not use heavy water for drinking.
Therefore, the option B is incorrect.
We must know that the physiological action of heavy water is definitely different from ordinary water due to the difference in masses. Therefore, the option C is correct.
We have to remember that the heavy water slows down reactions. The reactions involving heavy water proceed a slower rate as compared to ordinary water.
Therefore, the option D is incorrect.

Therefore, the option C is correct.

Note: We have to remember that the chemical properties of the heavier hydrogen-nucleus-with-a-neutron are slightly different, heavy water starts to gum up all manner of body parts if consumed in a large quantity. ${D_2}O$ which is more toxic to normal animal cells.Heavy water does occur naturally, however in much smaller quantities than ordinary water.