Question

quantas moleculas existem em 72 gramas de agua np estado solido.( massas atomicas H=1, O=16numero de avogadro=6,0

Answer 1

Massa molar H2O = 1 x 2 + 16 = 18 g/mol

1 mol H2O -------------- 18 g
x mol H2O --------------- 72 g

x = 72 / 18

x = 4,0 mols

1 mol  ------------------ 6,0 .10²³ moléculas
4,0 mols --------------- y moléculas

y = 4,0 . 6,0.10²³

y =  $2,4.10 ^{24}$ moléculas

espero ter ajudado!.