180 g CO2
nr.moli
nr. molecule
masa de oxigen
a. n=m: M n=nr. moli m=masa subst. M=masa molara
n=180g : 44g/moli=4,09 moli [ MCO2=12 +2.16=44--->1mol=44g ]
b.
1mol CO2 -------------6,023.10²³molecule
4, 09 moli ----------------------x
x=4,09.6,023 .10²³ molecule=
c.
44g CO2-----------32g O
180g-------------------x
x=180.32 : 44=130,9 g O