Respuesta :
Explanation:
Mole percentage of carbon = [tex]\frac{percentage given}{molar mass of carbon}[/tex]
= [tex]\frac{82.66}{12}[/tex]
= 6.89
Mole percentage of hydrogen = [tex]\frac{percentage given}{molar mass of hydrogen}[/tex]
= [tex]\frac{17.34}{1}[/tex]
= 17.34
Now, dividing mole percentage of both the atoms by 6.89.
Then, C = 1 and H = [tex]\frac{17.34}{6.89}[/tex] = 2.5
Hence, empirical formula is [tex]C_{2}H_{5}[/tex].
As, it is given that P = 556 mm Hg. Convert mm Hg into atm as follows.
[tex]\frac{556 mm Hg \times atm}{760 mm Hg}[/tex]
= 0.7316 atm
Volume is given as 158 mL. So, in liter volume is [tex]\frac{158}{1000}[/tex] equals 0.158 L.
According to ideal gas equation, PV = nRT
[tex]0.7316 atm \times 0.158 L = \frac{mass}{molar mass} \times 0.082 atm L/mol K \times 298 K[/tex]
[tex]0.7316 atm \times 0.158 L = \frac{0.275 g}{molar mass} \times 0.082 atm L/mol K \times 298 K[/tex]
molar mass = 58.2 g
Hence, molecular weight of [tex]C_{2}H_{5}[/tex] is [tex]12 \times 2 + 5[/tex] = 29.
Therefore, [tex](C_{2}H_{5})_{n}[/tex] = 58
29 × n = 58
n = 2
Thus, molecular formula of the compound is [tex]C_{4}H_{10}[/tex].
