Question

Que indica la formula empírica del Bromuro de Potasio (KBr)?
Que indica la formula empírica del Cloruro de Magnesio (MgCl2)?

Answer 1

KBr

Mm
K: 1 x 39 = 39 g/mol
Br: 1 x 80 = 80 g/mol
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       Mm = 119 g/mol

K: 

119 g ---- 100 %
  39 g -----  x
       x = 32.77 %

Br
119 g ---- 100 %
  80 g -----  x
       x = 67.22 %

K: 32.77 g / 39 g/mol = 0.84 mol
Br: 67.22 g/ 80 g/mol = 0.84 mol

dividir

K: 0.84 mol / 0.84 mol = 1
Br: 0.84 mol / 0.84 mol = 1

FE: KBr

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Mm: MgCl2

Mg: 1 x 24 = 24 g/mol
Cl: 2 x 35.4 = 70.8 g/mol
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            Mm =  94.8 g/mol

Mg: 

94.8 g ---- 100 %
  24 g -----  x
       x = 25.31 %

Cl
  94.8 g ---- 100 %
  70.8 g -----  x
       x = 74.68 %

Mg: 25.31  g / 24 g/mol = 1.054 mol
Cl: 74.68  g/ 35.4 g/mol = 2.109 mol

dividir

Mg: 1.054 mol / 1.054 mol = 1
Cl:  2.109 mol / 1.054 mol = 2

FE:MgCl2