Question

La composicion centesimal encontrada para una sustancia es c=40% h=6,4% y o=53,6% si la masa molecular debla sustancia es 90 gramoab¿cualbesvsu formula molecular , .

Answer 1

1. calcular moles

C: 40 g/ 12 g/mol = 3.33 mol
H: 6.4 g/ 1 g/mol = 6.4 mol
O: 53.6 g/ 16 g/mol = 3.35 mol

2. dividir entre el menor de los resultados

C: 3.33 mol / 3.33 mol = 1
H: 6.4 mol / 3.33 mol = 2
O: 3.35 mol / 3.33 mol = 1

3. F Empírica: CH2O

4. Calcular Mm de la FE

C: 1 x 12 = 12 g/mol
H:  2 x 1 = 2 g/mol
O:  1 x 16 = 16 g/mol
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       Mm = 30 g/mol

5. calcular n

n =   Mm del compuesto
      ```````````````````````````
          Mm de la FE

n = 90 g/mol / 30 g/mol

n = 3

6. FM = (CH2O)n = (CH2O)₆ = C₆H₁₂O₆