Question

Determinati nr.ul de moli de substanta pentru:
a) 12,044•10^24 atomi Ag
b) 78g K
c) 3600g C

Answer 1

1 mol-atomi contine 6,022x10^23 atomi, conform legii lui Avogadro

a)

1 mol-atomi Ag ............... 6,022x10^23 atomi Ag

n moli................................ 12,044•10^24 atomi Ag

=> n = 12,044•10^24 / 6,022x10^23 = 20 moli Ag

b)

1 mol K cantareste 39 g (masa atomica A = 39)

1 mol K ................. 39 g K

n moli K ................. 78 g K

=> n = 78x1/39 = 2 moli K

c)

1 mol C cantareste 12 g (vezi masa atomica A = 12)

1 mol C ................. 12 g C

n moli ................... 3600 g C

=> n = 3600x1/12 = 300 moli C