Question

The number of atoms of 4.25 g of NH3 is

Answer 1

Answer:

As mole=given mass/molecular mass.So mole of NH3 =4.25/20=425/2000. = 0.25 mole So number of atoms=0.25×6.022×10^23 atoms. As molecular mass of NH3 is 14+3=17g.

Answer 2

Answer:

Molar mass NH3 = 14+3 = 17g/mol

given mass = 4.25g

no of moles = 4.25/17 = 0.25 mol of NH3

1 mol of NH3 contains  6.022*10^23  molecules

0.25 mol NH3 contains  0.25*6.022*10^23  = 1.5055*10^23 molecules

1 molecule of NH3 contains 4 atoms

Number of atoms in 1.5055*10^23 molecules = 4*1.5055*10^23 atoms.

The correct answer is = 6.022*10^23 atoms