What is the molecular formula of this compound ? PZZZ HELP!?

Question

5.51 g of the compound fills a 193.0 ml bottle with a pressure of 4752.4 mm Hg at a temperature of 21.0oC.

65.45 % C

5.49 % H

29.06 % O

Answer 1

Ideal gas law states that

PV = nRT

P = pressure in atmospheres (760mm Hg = 1 atm)

V = in liters ( 1 L = 1000 ml)

n = no.of moles

T = temperature in Kelvin ( c+ 273.15)

R = gas constant = 0.08206 L. atm/mol.K

here

P = 4752.4 mm Hg = 4752.4/760 = 6.25 atm

V = 193 ml = 193/1000 = 0.193 L

T = 21 degrees C = 21+273.15 = 294.15 K

n = PV/RT = 6.25*(0.193)/(0.08206* (294.15)

n = 0.05 moles

so 0.05 moles = 5.51 g

1mole = 110.2 g

weight of carbon = 110.2(65.45/100) = 72.12

weight of Hydrogen = 110.2(5.49/100) = 6.04

weight of Oxygen = 110.2(29.06/100) = 32.02

moles of C = 72.12/12 = 6

moles of H = 6.04/1 = 6

moles of O = 32.02/16 = 2

so molecular formula is C6H6O2

Answer 2

Is the answer limited to a SINGLE compound? The empirical formulat of C3H3O does not make sense given your pressure and temperature.

Answer 3

By mass it looks like the ratios are 3H - 3C - 1O