Question

Relation between amu and molar mass?​

Answer 1

$\huge\texttt{Atomic Mass Of An Element:-}$

Actual masses of the atoms of the elements are very very small . For instance , one atom of hydrogen (H) has a mass of $1.673 × 10^{-24}$ gram . It is not convenient enough to use such complicated figures in our calculations , therefore , it was necessary to atomic masses in such a way that we get simple figures for them . To understand the present definition of atomic mass , it would br necessary to know two terms :

★ Carbon-12 atom .

★ Atomic Mass Unit .

◻ Carbon-12 atom is that atom of carbon which has 6 protons and 6 neutrons in its nucleus so that its mass number is 12 .

◻ One atomic mass unit is defined as exactly one-twelfth the mass of an atom of carbon-12 .

$\textbf{Carbon-12 atom}$ has been assigned an atomic mass of exactly 12 atomic mass units , therefore the atomic mass unit should be equal to $\frac{1}{12}$ the mass of a carbon-12 atom . The atomic mass of all other elements are determined by comparing the mass of their atom with the mass of a carbon-12 atom . So ultimately ,

$\textbf{Atomic Mass}$ : The relative mass of an atom as compared with the mass of a carbon-12 atom taken as 12 units .

$\huge\texttt{Molar Mass:-}$

The amount of a substance whose mass in grams is numerically equal to its atomic mass, is called the molar mass or $\textbf{Gram Atomic Mass}$ of the substance . Simply , the atomic mass of a substance expressed in grams is called its molar mass .

For example :-

Atomic Mass of Sodium = 23 u

Molar Mass of Sodium = 23 grams

Now , as it seems , the term $\textbf{Molar mass}$ is anyways related to the term $\textbf{Mole}$ . Now , let's know the term $\textbf{Mole}$ .

$\textbf{Mole:}$ 1 mole of atoms refers to $6.022 × 10^{23}$ atoms of the same substance .

★ $6.022\times10^{23}$ is known as $\textbf{Avogadro Number}$.

The molar mass of a substance represents the mass of 1 mole of atoms of that substance .

So , as discussed above , the relationship between Atomic mass Unit and Molar mass is very simple . We just need to keep in mind that atomic mass is expressed in atomic mass units and the molar mass is expressed in grams . The numericals remain the same .

And , there's a relationship between Moles , Avogadro number and Molar mass . It is as follows :

$1 mole = 6.022\times 10^{23} particles = Molar mass$