Respuesta :
Answer : The molecular of the compound is, [tex]C_8H_8[/tex]
Solution :
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of C = 92.26 g
Mass of H = 100 - 92.26 = 7.74 g
Molar mass of C = 12 g/mole
Molar mass of H = 1 g/mole
Step 1 : convert given masses into moles.
Moles of C = [tex]\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{92.26g}{12g/mole}=7.688moles[/tex]
Moles of H = [tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{7.74g}{1g/mole}=7.74moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C = [tex]\frac{7.688}{7.74}=0.99\approx 1[/tex]
For H = [tex]\frac{7.74}{7.74}=1[/tex]
The ratio of C : H = 1 : 1
The mole ratio of the element is represented by subscripts in empirical formula.
The Empirical formula = [tex]C_1H_1[/tex]
The empirical formula weight = 1(12) + 1(1) = 13 gram/eq
Now we have to calculate the molecular mass of polymer.
As, the mass of polymer of [tex]7.02\times 10^{18}[/tex] molecules = 1.22 mg = 0.00122 g
So, the mass of polymer of [tex]6.022\times 10^{23}[/tex] molecules = [tex]\frac{6.022\times 10^{23}}{7.02\times 10^{18}}\times 0.00122g=104.6g/mol[/tex]
Now we have to calculate the molecular formula of the compound.
Formula used :
[tex]n=\frac{\text{Molecular formula}}{\text{Empirical formula weight}}[/tex]
[tex]n=\frac{104.6}{13}=8[/tex]
Molecular formula = [tex](C_1H_1)_n=(C_1H_1)_8=C_8H_8[/tex]
Therefore, the molecular of the compound is, [tex]C_8H_8[/tex]
