in 90 g H2O se gasesc ? H si ?O
masa H = 2 x 1
masa molecula H2O = 2 x 1 + 16 = 18g
18g H2O ......... 2 moli de atomi de H
90g H2O ..........x
x = 90 x 2 / 18 = 10 moli at H
numarul de atomi de moli de oxigen
18g H2O ........ 1 mol atom O
90g H2O ..........x
x = 90/18 = 5 moli at oxigen
N Oxigen = 5 mol x 6,923 x 10 ²³ atom/mol atomi O = 34 x 10²³
N Hidrogen = 10 mol x 6,023 x 10²³ atom/mol atomi H = 60 x 10²³