i need help with this chemistry isu question, please help, would be greatly appreciated!!

Question

An organic compound used in the production of sweet-smelling perfumes was isolated and examined. It was found to contain the composition of 54.52 % carbon, 9.17% hydrogen, and the remaining percentage oxygen. In a second procedure, it was found that 1.76 g of the volatile liquid was able to fill a 288 mL Erlenmeyer flask at 99.8 kPa and 80°C.

a. Determine the empirical formula of the compound. 3 marks

b. Determine the molar mass of the compound. 5 marks

c. Determine the molecular formula of the compound. 2 marks

d.    Determine the empirical formula for this gas

Answer 1

The empirical formula is C₂H₄O (as described in the previous answer). This has a molar mass of 44 g/mol.

Now, we need to find the molecular formula. This can be done from the second procedure and using the Ideal Gas Law PV = nRT

P = pressure = 99.8 kPa

V = 288 ml = 0.288 L

n = moles = ?

R = gas constant = 8.314 L-kPa/Kmol

T = 353K

Solving for n: n = PV/RT = (99.8)(0.288)/(8.314)(353)

n = 0.00979 moles

molar mass = 1.76 g/0.00979 moles = 179.8 g/mol = 180 g/mol

molecular formula : 180/44 = 4 empirical formulae to make 1 molecular

molecular formula = 4 x C₂H₄O = C₈H₁₆O₂

Answer 2

The standard method for solving this type of problem is to think about a 100 g sample of this chemical

This sample would have 54.52 g Carbon, 9.170 g Hydrogen and 36.31 g oxygen.

The number of moles of carbon is thus 54.17 /12 = 4.543 moles carbon

the number of moles of hydrogen is 9.17 / 1 = 9.17 moles of hydrogen

the number of moles of oxygen is 36.31 /1 6 = 2.269 moles of oxygen

Dividing by the smallest of these numbers ( 2.269) leads to the empirical formula

C₂ O H₄

This is the formula for ethanal - a simple aldehyde. It has molar mass of 44 g

However, vinyl alcohol has the same structure.

vinyl alcohol has a higher vapor pressure than does ethanal, so hat might fit better with the flask data.