Question

Measurements show that unknown compound has the following composition: element mass % carbon(17.9%) hydrogen(2.26%) chlorine(79.7%) write the empirical chemical formula of .

Answer 1

The empirical formula of the compound is C2H3Cl3.

Step-by-step explanation:

The empirical formula of a compound is the simplest whole-number ratio of the atoms present in the compound. To determine the empirical formula, you need to convert the mass percentages of each element to moles. Then, divide each mole value by the smallest mole value to obtain the mole ratio. Finally, round the mole ratio to the nearest whole number to get the empirical formula.

In this case, we have 17.9% carbon, 2.26% hydrogen, and 79.7% chlorine. Assume we have 100g of the compound, which means we have 17.9g of carbon, 2.26g of hydrogen, and 79.7g of chlorine.

Next, we convert each mass to moles using the molar mass. The molar mass of carbon is 12.01 g/mol, hydrogen is 1.01 g/mol, and chlorine is 35.45 g/mol

The number of moles is calculated by dividing the mass by the molar mass. For carbon, we have 17.9g / 12.01 g/mol = 1.49 mol. For hydrogen, we have 2.26g / 1.01 g/mol = 2.24 mol. And for chlorine, we have 79.7g / 35.45 g/mol = 2.24 mol.

Finally, we divide each mole value by the smallest mole value to obtain the mole ratio. In this case, carbon has the smallest mole value of 1.49 mol. So, the mole ratio becomes 1:1.5:1.5.

Rounding each mole ratio to the nearest whole number gives us the empirical formula of the compound, which is CH1.5Cl1.5. However, since an empirical formula can't have fractional subscripts, we need to multiply all the subscripts by 2 to get the simplest whole-number ratio. Therefore, the empirical formula of the compound is C2H3Cl3.

Answer 2

The empirical chemical formula of the unknown compound with the given composition of carbon (17.9%), hydrogen (2.26%), and chlorine (79.7%) is C1.49H2.24Cl2.25.

Step-by-step explanation:

To determine the empirical chemical formula of the unknown compound, we first need to convert the given mass percentages to the number of moles for each element.

First, assume we have a 100 gram sample of the compound. We can calculate the mass of each element in grams by multiplying the mass percentage by the total mass of the compound:

• Mass of Carbon (C) = 17.9% x 100 g = 17.9 g
• Mass of Hydrogen (H) = 2.26% x 100 g = 2.26 g
• Mass of Chlorine (Cl) = 79.7% x 100 g = 79.7 g

Next, we need to convert these masses to moles by dividing by the molar mass of each element:

• Moles of Carbon (C) = 17.9 g / 12.01 g/mol = 1.49 mol
• Moles of Hydrogen (H) = 2.26 g / 1.008 g/mol = 2.24 mol
• Moles of Chlorine (Cl) = 79.7 g / 35.45 g/mol = 2.25 mol

Finally, we divide the number of moles by the smallest number of moles to get the empirical formula:

• Empirical formula = C1.49H2.24Cl2.25