Question

How many moles are present in

a.12g of Nitrogen molecule.

b. the following particles of oxygen
$12.044 \times {10}^{23}$


​

Answer 1

Answer: (a) There are 0.428 moles present in 12 g of $N_{2}$ molecule.

(b) There are 2 moles present in $12.044 \times 10^{23}$ particles of oxygen.

Explanation:

(a). The mass of nitrogen molecule is given as 12 g.

As the molar mass of $N_{2}$ is 28 g/mol so its number of moles are calculated as follows.

$No. of moles = \frac{mass}{molar mass}\\= \frac{12 g}{28 g/mol}\\= 0.428 mol$

So, there are 0.428 moles present in 12 g of $N_{2}$ molecule.

(b). According to the mole concept, 1 mole of every substance contains $6.022 \times 10^{23}$ atoms.

Therefore, moles present in $12.044 \times 10^{23}$ particles are calculated as follows.

$Moles = \frac{12.044 \times 10^{23}}{6.022 \times 10^{23}}\\= 2 mol$

So, there are 2 moles present in $12.044 \times 10^{23}$ particles of oxygen.