Question

Scrieti formula substantei formata din potasiu si oxigen.Calculati masa moleculara ,raportul de masa si compozitia procentuala a substantei
Multumesc

Answer 1

K2O

Masa moleculara:

M K2O=2*39+16=78+16=94

Raportul de masa:

m K: m O=2*39:16=78:16=39:8

Compozitia procentuala:

78 g K......16 g O......94 g K2O
   x...............y............100 g K2O

$x= \frac{7800}{94}=82,98$
$y= \frac{1600}{94}=17,02$

Deci in K2O exista 82,98% K si 17,02% O.

Answer 2

K2O
M = 94g/mol 
mK : mO = 78 : 16 = 39 : 8
%K = 78·100/94 = 82,978%    %O = 1600/94 = 17,021%