Question

The number of mole of nitrogen in 1litre of air containing \[10\% \] nitrogen by volume under standard condition is:
A. 0.03 mole
B. 2.10 mole
C. 0.186 mole
D. $4.46 \times {10^{ - 7}}$ mole

Answer 1

Hint: The mole is the measurement or the base unit for the amount of substance present in the given sample. These particles can be of any type of species, e.g. Atoms, molecules, electrons, protons, neutrons etc. As long as the gas is ideal, 1 mole= 22.4L Volume percentage is a measure of the concentration of a substance in a solution. It is expressed as the ratio of the volume of the solute to the total volume of the solution multiplied by 100.

Complete step by step answer:
Given that: 1l of air contains \[10\% \] nitrogen by volume.
Therefore,
Volume of nitrogen in the mixture \[ = \dfrac{{10}}{{100}} = \times 1 = 0.1{\text{ }}L\]
Now at STP, (Standard temperature and Pressure)
As we know, I mole of gas = 22.4 L
Therefore,
No of moles of nitrogen in 0.1 L ,
   \[
  \; = \dfrac{1}{{22.4}} \times {\text{ }}0.1 \\
   = {\text{ }}4.46 \times {\text{ }}{10^{ - 3}} \\
 \] mol
Hence, the number of molecules of nitrogen in 1 L of air containing \[10\% \] nitrogen by volume under standard conditions is \[4.46 \times {10^{ - 3}}\]mol

Hence option D is correct.

Additional information:
At STP, a system is said to have a temperature of zero degrees centigrade (273 Kelvin) and the pressure equal to the atmosphere is always 1 atm. Additionally, one mole of any gas at STP occupies a volume of 22.414L. Remember this concept only holds true for gases.
Nitrogen makes up around \[79\% \] of the air you breathe.
It is an inert gas, meaning it doesn’t chemically react with other gases and it isn’t toxic. But breathing pure nitrogen is deadly. That’s because the gas displaces oxygen in the lungs.
Further liquid nitrogen is dangerous if not handled properly. It can cause frostbite or cryogenic burns and if used or spilled in a confined space, it can kill. It is as shown:

Note:
 1 mole is the number which is equal to \[6.022 \times {10^{ - 23}}\] particles, also known as Avogadro’s constant. It is the proportionality factor that relates the number of constituent particles in a sample with the amount of substance in that sample.