Question

0.487grams of quinine(molar mass = 324g/mol) is combusted and found to produce 1.321 g co2, 0.325g h2o and 0.0421 g nitrogen. determine the emperical and molecular formula ? i

Answer 1

To determine the empirical formula, we convert the mass of elements released upon combustion into moles, arrive at the simplest whole number ratio, and then compare the empirical formula mass to the given molar mass to find the molecular formula.

Step-by-step explanation:

Empirical and Molecular Formula Calculation

To find the empirical formula of a compound, we start by converting the masses of the elements formed upon combustion to moles. The molar mass of carbon (C) is 12 g/mol, for hydrogen (H) it's 1 g/mol, and for nitrogen (N) it's 14 g/mol. From the mass of CO2 produced, we find the moles of carbon, and from the mass of H2O, the moles of hydrogen. The moles of nitrogen are calculated directly from the given mass of nitrogen.

Next, to determine the empirical formula, we use these moles to get the simplest whole number ratio. We then compare the empirical formula mass to the molar mass given in the question (324 g/mol) to find the molecular formula. The ratio of the molecular mass to the empirical formula mass tells us how many empirical units are in the molecular formula.

Given the information in the question, we would perform the necessary conversions to find the moles of each element and then derive the empirical and molecular formulas, which would be supported by clearly showing the calculation steps.

Answer 2

The empirical formula of quinine is C10H6N and the molecular formula is C20H12N2.

Step-by-step explanation:

In order to determine the empirical and molecular formula of quinine, we need to calculate the mole ratios of carbon, hydrogen, and nitrogen in the given compounds. We start by converting the given masses of CO2, H2O, and nitrogen to moles using their respective molar masses. For CO2, the molar mass is 44 g/mol, so moles of CO2 = 1.321 g / 44 g/mol = 0.03 mol. Similarly, for H2O, the molar mass is 18 g/mol, so moles of H2O = 0.325 g / 18 g/mol = 0.018 mol. And for nitrogen, the molar mass is 14 g/mol, so moles of nitrogen = 0.0421 g / 14 g/mol = 0.003 mol.

Next, we calculate the mole ratios of these elements. The ratios are as follows: C:N = 0.03 mol : 0.003 mol = 10 : 1, and H:N = 0.018 mol : 0.003 mol = 6 : 1. These ratios are close to whole numbers, so the empirical formula can be written as C10H6N. The empirical formula mass for this compound is 160.19 g/mol.

The molar mass of quinine is given as 324 g/mol. Comparing the molar mass and empirical formula mass, we can see that each quinine molecule contains two empirical formula units, so the molecular formula of quinine is 2(C10H6N), which can be simplified as C20H12N2.