Final answer:
To determine succinic acid's empirical and molecular formulas, one must calculate moles of carbon and hydrogen from CO₂ and H₂O produced, determine moles of oxygen, and find their ratios. The molecular formula is deduced by comparing the molar mass of the empirical formula with the compound's given molar mass, as exemplified by acetic acid.
Step-by-step explanation:
To determine the empirical and molecular formulas of succinic acid from combustion analysis, we first calculate the moles of carbon and hydrogen using the masses of CO₂ and H₂O produced. Each mole of CO₂ contains one mole of carbon, so by dividing the mass of CO₂ by its molar mass (44.01 g/mol), we find the moles of carbon. Similarly, every two moles of H₂O contain two moles of hydrogen, so by dividing the mass of H₂O by its molar mass (18.02 g/mol) and then by 2, we get the moles of hydrogen.
To find the moles of oxygen in succinic acid, we subtract the mass of carbon and hydrogen (as part of CO₂ and H₂O) from the initial mass of succinic acid burned. The difference gives us the mass of oxygen, which we can then divide by its molar mass (16 g/mol) to get the moles of oxygen. Using the smallest number of moles calculated for these elements, we find their ratio to determine the empirical formula.
To find the molecular formula, we compare the molar mass of the empirical formula with the given molar mass of the substance. By dividing the given molar mass by the molar mass of the empirical formula, we find a ratio that tells us how many times the empirical formula must be multiplied to reach the molecular formula.
For instance, acetic acid has a given molar mass of 60.05 g/mol, whereas its empirical formula CH₂O has a molar mass of 30.02 g/mol. This implies that the molecular formula of acetic acid must be twice the empirical formula, which results in the molecular formula C₂H₄O₂, denoted as CH₃COOH.