Question

How many moles of NaCl are present in 20 g of NaCl?

Answer 1

Hint: We know that the mol is an SI unit which is used to donate the number of particles in a given substance. Here, we have to calculate the moles of NaCl present in 20 g of NaCl. For that, we have to use the formula, Number of moles=\[\dfrac{{{\text{Mass}}}}{{{\text{Molar}}\,{\text{mass}}}}\].

Complete step by step answer:
Let’s first calculate the molar mass of NaCl. We know the atomic mass of sodium is 23 ${\text{g}}\,{\text{mo}}{{\text{l}}^{ - 1}}$ and atomic mass of Chlorine 35.5 ${\text{g}}\,{\text{mo}}{{\text{l}}^{ - 1}}$.
So, the molar mass of NaCl = 35.5 ${\text{g}}\,{\text{mo}}{{\text{l}}^{ - 1}}$ +23 ${\text{g}}\,{\text{mo}}{{\text{l}}^{ - 1}}$= 58.5 ${\text{g}}\,{\text{mo}}{{\text{l}}^{ - 1}}$.
Now, we have to use the following formula to calculate the number of moles of NaCl. The mass of NaCl is given as 20g.
Number of moles=\[\dfrac{{{\text{Mass}}}}{{{\text{Molar}}\,{\text{mass}}}}\].
$ \Rightarrow $Moles of NaCl=$\dfrac{{20\,{\text{g}}}} {{58.5\,{\text{g}}\,{\text{mo}}{{\text{l}}^{ - 1}}}} = 0.342\,{\text{mol}}$

So, the number of moles of NaCl present in 20 g of NaCl is 0.342 mol.

Additional information:
The mole or mol (abbreviation form) is the unit which measures the amount of substance present. A mole is the term that defines the number of carbon (C) atoms in 12 g of pure carbon. After so many years of experiment, it has been proved that a mole of anything contains \[6.022 \times {10^{23}}\] representative particles.

Note: It is to be noted that NaCl is also called as common salt. It is beneficial for our body. It has the function to absorb or transport nutrients. It maintains the blood pressure and maintains the right balance of fluid in the body.