Question

What is the mass of $C{{O}_{2}}$ in grams?

Answer 1

Hint: We know that to understand the term molar mass, let us break it in mole + mass. It means it is the mass of one mole of a substance. Molar mass can be calculated easily by adding the masses of individual elements which makes up the compound.

Complete step by step answer:
Let us understand the meaning of molar mass. The molar mass is the weight of one sample mole of a substance. To find out the molar mass, undergo the following steps.
Write all the atoms of elements present in the given compound. For example, here in this question the compound given is $C{{O}_{2}}$ and it contains three atoms (one of carbon +two of oxygen).
Find the atomic mass of each element using the mass shown in the periodic table or atomic weight table. Here, in this question the atomic weight of carbon is $12$ amu and the atomic mass of oxygen $=16$ amu.
Multiply the number of atoms of a n element with its atomic mass and add all the masses so obtained. In this question there is only one atom of carbon and its mass is $12$ amu. Also, there are two atoms of oxygen so their mass will be two times the atomic mass of oxygen Therefore; molar mass of Carbon dioxide $C{{O}_{2}}$ is as follows;
Atomic mass of carbon $+2$(atomic mass of oxygen)
$12+2(16)=12+32=44$
Thus, $Mass=\dfrac{1}{\left( 6.022\times {{10}^{23}} \right)\times 44}$
\[\Rightarrow Mass=7.3065\times {{10}^{23}}gm\]
Therefore, the mass of $C{{O}_{2}}$ in \[7.3065\times {{10}^{23}}gm\]

Note: Note that it is always suggested to learn the atomic mass of basic elements such as carbon, oxygen etc. as then it becomes very easy to just calculate the molar mass. It should be noted that the number of entities (atoms/molecules) contained in molar mass is equal to the Avogadro number \[\left( 6.02\times {{10}^{23}} \right).\]