Question

Alcatuieste formulele oxizilor dupa valenta elementelor si calculeaza masa molara a lor. NaO,Fe(3)O,N(5)O,Fe(2)O,Pb(6)O,Cr(4)O.Va rog rapid

Answer 1

Na₂O----->oxid de sodiu
M=(2*23)+16=46+16=62 g/mol

Fe₂O₃--->oxid de fier III
M=(2*56)+(3*16)=112+48=160 g/mol

N₂O₅----->pentaoxid de azot
M=(2*14)+(5*16)=28+80=108g/mol

FeO----->oxid de fier II
M=56+16=72 g/mol

PbO₃---->trioxid de plumb
M=207,2+(3*16)=207,2+48=255,2 g/mol

CrO₂----->dioxid de crom
M=52+(2*16)=52+32=84 g/mol