Question

Oxidul bazic al unui element chimic monovalent contine 74,2% oxigen. Formula chimica este:
a) Na2O
b) F2O
c) Li2O

Answer 1

contine 74,2% metal ..... si nu oxigen

oxid bazic = oxid metalic, meatl monovalent

=> M2O

=> 100% ....................... 74,2% M

   2M+16 ......................... 2M g metal

=> M = 16/0,7 = 23 u.a.m => M = Na

=> Na2O => a)