Question

Calculate the no of atoms in 1.4 g of nitrogen gas

Answer 1

Answer: $6.023\times 10^{22}$ atoms

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 Liters at STP and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}$

$\text{Number of moles of nitrogen gas}=\frac{1.4g}{28g}=0.05moles$  

Now 1 mole of $N_2$ molecule contains = $2\times 6.023\times 10^{23}=12.04\times 10^{23}$ atoms

0.05 moles of $N_2$ molecule contains = $\frac{12.04\times 10^{23}}{1}\times 0.05=6.023\times 10^{22}$ atoms

The no of atoms in 1.4 g of $N_2$ is $6.023\times 10^{22}$ atoms.