Question

Heavy water is:
$(a)$ Compound of deuterium and oxygen
$(b)$ Water at ${4^0}C$
$(c)$ Water in which soap does not lather
$(d)$ Compound of heavy oxygen and heavy hydrogen

Answer 1

- Hint: In this question use the concept that heavy water simply contains isotopes of water and has the general chemical formula of${D_2}O$. There is a large difference between the densities of normal water and heavy water that is 11%. This differentiates the properties of heavy water with respect to normal water. This will help approach the solution to this problem.

Complete step-by-step solution :
As we know that heavy water is another form of water which contains the isotope of the hydrogen called deuterium often denoted by D.
Because of this the physical and the chemical properties of the water are changed due to increase in mass as the mass of the deuterium is greater than the normal isotope of the hydrogen which is present in normal water (i.e. protium).
The presence of deuterium also gives us changed nuclear properties that’s why it is used in nuclear reactors as a moderator, it is also not radioactive.
As we know that in a single molecule of a heavy water it contains two atoms of deuterium and one atom of oxygen as compared to normal water, in normal water it contains two atoms of protium and one atom of oxygen.
The chemical formula of heavy water is ${D_2}O$ whereas the chemical formula for normal water is ${H_2}O$.
It has a density about 11% greater than the normal water.
So the heavy water is the compound of deuterium and oxygen.
So this is the required answer.
Hence option (A) is the correct answer.

Note – In general there are three isotopes of hydrogen that are protium, deuterium and tritium. The atomic masses of the three isotopes are A=1, A=2 and A=3 respectively. Deuterium is quite commonly used in organic chemistry to study the basic reactions. Heavy oxygen is a stable isotope of oxygen and it is not the part of formation of heavy water.