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6.00 g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 26. g/mol, is burned completely in excess oxygen, and the mass of the products carefully measured:
product mass
carbon dioxide 20.31g
water 4.16 g
Use this information to find the molecular formula of X

Respuesta :

Answer:

C2H2

Explanation:

Mass of Carbon in CO2[tex]= (12/44) (20.31)[/tex] grams [tex]= 5.54[/tex] gram

Mass of hydrogen in H2O [tex]= (2/18)(4.26)[/tex] grams [tex]= 0.46[/tex] gram

We will calculate the % of C and H in the sample  

% C [tex]= (5.54/6) * 100 = 92[/tex]%

% H [tex]= (0.46/6)*100 = 7.7[/tex]%

Number of mole of C [tex]= 92/12 = 7.69[/tex]

Number of mole of H [tex]= 7.67/1 = 7.67[/tex]

Fractional share of  C [tex]= 7.69/7.67 = 1[/tex]

Fractional share of  H [tex]= 7.67/7.67 = 1[/tex]

Empirical Formula = CH

Empirical Mass [tex]= 12+1 = 13[/tex]

Molecular mass [tex]= 26[/tex]

Molecular Formula – CHn  

N [tex]= 26/13 = 2[/tex]

Molecular Formula = C2H2

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