Question

Calculate the mass of 1 ammonia molecule

Answer 1

The atomic masses of N and H are 14 g/mole and 1 g/mole respectively. The molecular weight of ammonia is 14+3(1)=17 g/mole.

Convert unit from g to kg

17 g/mole ×

1000 g

1 kg

=0.017 kg/mole

1 mole of ammonia weighs 0.017 kg and contains Avogadro's number ( 6.023×10

23) of molecules

Molecular mass of an ammonia molecule =

6.023 ×10

23

molecules/mole

0.017 kg/mole

=2.82×10

−26

kg