Question

Dos compostos a seguir, qual apresenta massa molecular igual a 30? *

(A) C₂H₆
(B) PH₃
(C) NH₃
(D) NO₂
(E) N₂O₃

Answer 1

C₂H₆ => 2 . 12 + 6 . 1 = 24 + 6 = 30

PH₃ = 30.1 + 3.1 = 30 + 3 = 33

NH3 = 14.1 + 3.1 = 14 + 3 = 17

NO₂ = 14.1 + 16.2 =14 + 32 = 46

N₂O₃ = 14.2 + 16.3 = 28 + 48 = 76

R.: Letra A.