Question

Quantos átomos de oxigênio existem em:

a) 32,543 g de O2
b) 2,454 mols de NaOH
c) 2,454 mols de Mg(NO3)2
d) 32,7493 kg de CH3COOH
e) 6869,4 toneladas (t) de Fe(OH)3

Answer 1

Podemos resolver isso com simples regras de 3:

a) 32,543g-----12.10^23

32g---------------X

32×12.10^23 = 384.10^23

32,543×X= 32,543x

32,543x=384.10^23

x=384.10^23/32,543

x=11,79.10^23

x= 1,179.10^24 átomos de O2

b) 1mol------- 6.10^23

2,454mols--- x

x= 2,454×6.10^23

x= 14,724.10^23

x= 1,4724.10^24 Átomos de O

c) 1mol --------- 36.10^23

2,454mols---- x

x=2,454×36.10^23

x=88,344.10^23

x= 8,8344.10^24 átomos de O6

d)0,0327493g------12.10^23

60g -----------------------x

0,327493x=720

x=720/0,0327493

x=21985,20.10^23

x=2,198520.10^27átomos de O2

e) 0,0068694g--------18.10^23

107g---------------------x

0,0068694x= 1926.10^23

x=1926/0,0068694

x= 280373,83.10^23

x=2,8037383.10^28 átomos de O3