# A) Determine the number of atoms for each element present in the following molecule: Na_2CO_3 B)...

## Question:

A) Determine the number of atoms for each element present in the following molecule:

{eq}Na_{2}CO_{3}{/eq}

B) Using the periodic table of elements, determine the molar mass for this molecule.

## Atoms and molar mass

A compound can be made up of different atoms and is represented in the chemical formula. The subscripts represent the number of atoms that are present per compound. The molar mass of the compound is equal to the individual mass of each atom added together to represent the mass of 1 mole of the compound.

In {eq}Na_2CO_3{/eq} there are 2 atoms of Na, 1 atom of C and 3 atoms of O.

The molar mass is equivalent to the mass of all the atoms:

Na: {eq}2 \times 28.9898 = 45.9796{/eq}

C: {eq}1 \times 12.0111 = 12.0111{/eq}

O: {eq}3 \times 15.9994 = 47.9982{/eq}

The mass of {eq}Na_2CO_3 = 45.9796 + 12.0111 + 47.9982 = 105.9901 g/mol{/eq}