Jika diketahui massa atom relatif Ar : N = 14; H = 1 dan tetapan avogadro = 6 x 10^23, dalan 8 gram N2H4 terdapat atom nitrogen sebanyak ...

N = 2 × 8/32 × 6×10^23 = 3×10^23 atom

Mr N2H4 = (2xArN)+(4xArH)
= (2x14)+(4x1) = 28 + 4 = 32

n N2H4 = massa / Mr = 8/32 = 1/4

JP N2H4 = n x L
= 1/4 x 6 x 10^23
= 1,5 x 10^23