Question

calculate the no of moles present in :
a)18g of mg (mg=24)
b)12.044 x 10^22 no of neon atom

Answer 1

a) No. of moles = given mass/ molar mass 
= 18/24 = 3/4 =0.75 moles 

b) No. of moles = given no. of particles/avagardo no.
= 6.022 x 10^22 / 12.044 x 10^22 = 2 moles

Answer 2

Number of Moles= Given mass$\frac{given mass}{gam}$
=18/24=3/4 mol

b.Number of mole= given number/Na
=12.044*10²²/6.022*10²²=2 mol