Question

The weight of one mole of heavy water is:
1.$18gm$
2.$20gm$
3.$19gm$
4.$21gm$

Answer 1

This question gives the knowledge about the mole concept. The mole concept is a very important method which is used in explaining the amount of various substances. The unit of mole is $mol$ which is used to measure the amount of variety of particles.

Complete step-by-step answer: The chemical name for heavy water is deuterium oxide and whose chemical or molecular formula is ${D_2}O$. Deuterium oxide contains two atoms of deuterium and one atom of oxygen. The molecular mass is the sum of the atomic masses of individual atoms present in the molecule. The molecular weight of heavy water is $20$.
The mole concept is a very important method which is used in explaining the amount of various substances. The unit of mole is $mol$ which is used to measure the amount of variety of particles.
What is a mole?
A mole is a measurable quantity that is defined as the number of particles which contains $6.022 \times {10^{23}}$ entities of the provided substance.
The weight of one mole of heavy water is determined as follows:
The molecular mass of heavy water is $20$.
As we know, the weight of one mole of a molecule is equal to the molecular mass of that molecule.
Therefore, the weight of one mole of heavy water is $20gm$.

Hence, option $2$ is the correct option.

Note: Mole is a quantitative property which helps in specifying the amount of a substance. Mole is used as a way of representing the amount of products and reactants present in the chemical reactions. The antiquity of mole entangled with the atomic mass units, molecular mass and the Avogadro’s number.