Cate molecule de apa se gasesc in 0,1g si 0,5g apa?

 1 mol H₂O ........................... 18 g H₂O

    x moli H₂O ........................  0,1 g H₂O

x=0,1/18

x=0,005 mol

 1 mol H₂O ........................... 18 g H₂O

    x moli H₂O ........................  0,5 g H₂O

x=0,5/18

x=0,027 mol

1 mol ................................. 6,023 * 10 ²³ molecule

 0,005 moli ............................... 6,023 * 10²³ *0,005 =30,115*10²⁰molecule apa

1 mol ................................. 6,023 * 10 ²³ molecule

 0,027 moli ............................... 6,023 * 10²³ *0,027=168,21*10²⁰ molecule apa

Bafta!