Question

Determinați câți moli și câte molecule de apa se găsesc într un gram de apa

Answer 1

H2O                                                                                                      M=2+16=18------>1mol=18g     23
18g---------1mol----------6,023. 10                                                                                 1g-----------xmoli----------y molecule H2O                                                                                                                      x=1.1:18=0,05moli H2O
                                                 23
Y=1. 6,023.10    :18=0,3346.10    molecule H2O

Answer 2

m H2O = 1 g
n H2O = m H2O / M H2O
n H2O = 1 g/18(g/mol) = 0.056 mol H2O

1 mol H2O contine 6.0223 x 10^23 molecule
atunci
0.056 mol H2O contin a molecule H2O
a = 0.056 x 6.0223x10^23 molecule= 3.37x10^22 molecule