To determine the empirical formula of the compound, we need to find the ratio of the atoms present. Let's start by calculating the number of moles for each element in the given sample:
Hydrogen (H): From the given information, we know that 9.00 g of the compound contains 4.19 × 10^23 H atoms. We can use Avogadro's number (6.022 × 10^23) to convert the number of atoms to moles: Number of moles of H = (4.19 × 10^23 atoms) / (6.022 × 10^23 atoms/mol) ≈ 0.695 mol
Chlorine (Cl): Since the compound contains 55.0% Cl by mass, we can calculate the mass of Cl in 9.00 g of the compound: Mass of Cl = (55.0% Cl) × (9.00 g) = 4.95 g Next, we can find the number of moles of Cl using its molar mass: Molar mass of Cl = 35.45 g/mol (from the periodic table) Number of moles of Cl = (4.95 g) / (35.45 g/mol) ≈ 0.139 mol
Carbon (C): The remaining mass in the compound can be attributed to carbon: Mass of C = (9.00 g) - (4.95 g) = 4.05 g We can find the number of moles of C using its molar mass: Molar mass of C = 12.01 g/mol (from the periodic table) Number of moles of C = (4.05 g) / (12.01 g/mol) ≈ 0.337 mol
Now, we have the number of moles for each element. To determine the empirical formula, we need to find the simplest whole number ratio between the elements. We can divide each number of moles by the smallest value (0.139 mol in this case):
H: 0.695 mol / 0.139 mol ≈ 5 C: 0.337 mol / 0.139 mol ≈ 2 Cl: 0.139 mol / 0.139 mol = 1
The ratio of the elements is approximately H5C2Cl1. However, we want to express it in the simplest whole number ratio, so we divide all the subscripts by the smallest subscript (1):
H5C2Cl1 becomes H5C2Cl
Therefore, the empirical formula of the compound is H5C2Cl.