Calculate the following quantities in 5.6 g of nitrogen

Calculate the following quantities in 5.6 g of nitrogen. (Atomic mass of N = 14 u)
(i) Number of moles of nitrogen
(ii) Number of molecules of nitrogen
(iii) Number of atoms of nitrogen
or
A vessel contains 5.6 grams of nitrogen gas. Calculate the number of moles of nitrogen gas, number of nitrogen molecules and number of nitrogen atoms if the atomic mass of per mole.

Atomic mass of nitrogen = 14 u
Molar mass of ${{N}{2}}$ = 2 X 14 = 28 g/mol
(i) Number of moles of nitrogen = Given mass / molar mass = 5.6 / 28 = 0.2 mol
(ii) Number of mole of nitrogen = Given mass / molar mass x Avagadro number = m/M x ${{N}
{A}}$
n = 5.6 / 28 x 6.022 x ${10}^{23}$ = 1.0244 x ${10}^{23}$ molecules.
(iii) One molecule of nitrogen contains two atoms of nitrogen .
Number of nitrogen = 2 x number of nitrogen molecules= 2 x 1.2044 x ${10}^{23}$ = 2.4088 x ${10}^{23}$