Question

56g nitrogen is taken. (atomic mass-14)
(a) Calculate the number of moles of nitrogen molecules present in it.
(b) Calculate the number of atoms​​

Answer 1

Explanation:

no. of moles=given weight/molecular weight

=56/2(14)

=56/28

=2

no. of atoms=no.of molecules*total no. of atoms

=moles*NA*total no. of atoms of N2

=2*6.022*10²³*2

=4*6.022*10²³

=24.088*10²³

=2.4088*10²⁴

Answer 2

Question:-

If 56g of nitrogen is taken. (Atomic mass of nitrogen = 14)

(a) Calculate the number of moles of nitrogen molecules present in it.

(b) Calculate the number of atoms​​

Answer:-

(a) Molar mass of nitrogen = Atomic mass of nitrogen × 2

                                       = 14 × 2

                                       = 28u

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

                             = $\frac{56}{28}$

                             = 2 moles

(b) 1 mole = 6.022 × 10²³ (Avogadro's number)

Number of atoms = Number of moles × Avogadro's number

                              = 2 × 6.022 × 10²³

                              = 12.044 × 10²³

Hope this helps! ♡