A 3.000 gram sample of an unknown compound containing the elements carbon, hydrogen, and nitrogen is analyzed by combustion. The combustion releases 4.714 grams of carbon dioxide and 1.500 grams of nitrogen. If 25 molecules have a combined mass of 4.65 x 10⁻²¹ grams, what is the compound's molecular formula?

Thank you.,

Convert 4.714g CO2 to g C.

Convert 1.500g N2 to g N.
g H = 3.00-gC-gN

moles C = ?
moles H = ?
moles N = ?
Find the empirical formula.
The molar mass will be
4.65E-21 x (6.022E23/25) = ?
Then (molar mass/empirical mass) = n which you round to a whole number, then
molecular formula = (empirical formula)n
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To determine the molecular formula of the unknown compound, we need to calculate the molar masses of carbon, hydrogen, and nitrogen using the given data and then compare them with the molar masses obtained from the molecular formula options.

We are given that the combustion of a 3.000 gram sample of the unknown compound produces 4.714 grams of carbon dioxide (CO2) and 1.500 grams of nitrogen (N2). To find the mass of carbon and nitrogen in the unknown compound, we need to subtract the mass of oxygen from the total mass of carbon dioxide (CO2) and the mass of nitrogen from the total mass of nitrogen (N2).

Mass of carbon = mass of carbon dioxide - mass of oxygen
Mass of carbon = 4.714 g - (2 x molar mass of oxygen)
Mass of carbon = 4.714 g - (2 x 16.00 g/mol) [Molar mass of oxygen = 16.00 g/mol]
Mass of carbon = 4.714 g - 32.00 g/mol
Mass of carbon = -27.286 g/mol

The negative value for the mass of carbon implies an error, and thus, the given data is not consistent. Please double-check the data provided and ensure its accuracy.