Question

Determinati formula procentuala pt acidul fosforic.

Answer 1

M H₃PO₄ = 3AH + AP + 4AO = 3*1 + 31 + 4* 16= 3 +31 + 64= 98
M= masa moleculara; A = masa atomica
( daca la) 98 g H₃PO₄........ 3% H ..........31%  P................64% O
 (dar la) 100g H₃PO₄ .......x% H ..........y% P .........z %O
x= 3*100 /98 = 3,06 % H
y= 31*100 /98 =31,63 % P
z= 64*100 /98 = 65,3 % O 
Sper ca te-am ajutat.:)