A1.367g sample of an unknown organic compound is combusted with oxygen to give only 1.459 g H2o and 3.055 g of Co2. What is the empirical formula of the compound?

Does the compound contain ONLY C and H? If so, then convert grams CO2 to moles C and convert grams H2O to moles H (H and not H2).

Then find the ratio of C and H to each other with the smallest number being 1.00.
Frankly, I think you have made an error in posting because if I add g carbon and g hydrogen, I don't end up with 1.367g unknown. So the extra mass could be due to oxygen, nitrogen, sulfur, or some other element. Check your post.

To find the empirical formula of the unknown organic compound, we need to determine the mole ratio of the elements present in the compound based on the given mass of each element.

1. Start by calculating the number of moles for each element:

- Hydrogen (H2O): mass = 1.459 g
molar mass of H2O = 2(1.01) + 16.00 g/mol = 18.02 g/mol
moles of H2O = 1.459 g / 18.02 g/mol = 0.081 moles

- Carbon (CO2): mass = 3.055 g
molar mass of CO2 = 12.01 + 2(16.00) g/mol = 44.01 g/mol
moles of CO2 = 3.055 g / 44.01 g/mol = 0.069 moles

2. Once we have the moles for each element, we need to find the simplest mole ratio of H and C. To achieve this, we divide the number of moles by the smallest value (in this case, carbon):

- moles of H = 0.081 moles / 0.069 moles ≈ 1.174
- moles of C = 0.069 moles / 0.069 moles = 1.000

3. Next, we round the moles to the nearest whole number to obtain whole number ratios:

- moles of H = 1
- moles of C = 1

4. Finally, we can form the empirical formula using the found whole number ratios:

- The empirical formula of the unknown organic compound is CH.

Therefore, the empirical formula of the compound is CH.