Determine the empirical and molecular formula for chrysotile asbestos. Chrysolite has the following percent composition: 28.03% Mg, 21.20% Si, 1.16 % H, and 49.21% O. The molar mass of chrysotile is 520.8 g/mol.

To determine the empirical and molecular formula for chrysotile asbestos, we need to find the relative numbers of atoms of each element in the compound. Given the percent composition and molar mass of chrysotile, we can follow these steps:

Step 1: Convert the percent composition to grams.
Step 2: Convert the grams to moles using the atomic masses of each element.
Step 3: Find the simplest whole-number ratio of the elements to get the empirical formula.
Step 4: Calculate the molecular formula using the molar mass and empirical formula.

Let's start the calculations:

Step 1: Convert the percent composition to grams.

Assuming we have 100 g of chrysotile, the masses of each element are as follows:

Mg: 28.03 g
Si: 21.20 g
H: 1.16 g
O: 49.21 g

Step 2: Convert the grams to moles.

Using the atomic masses:
Mg: 24.305 g/mol
Si: 28.0855 g/mol
H: 1.0079 g/mol
O: 16.00 g/mol

Moles of each element:
Mg: 28.03 g / 24.305 g/mol ≈ 1.152 moles
Si: 21.20 g / 28.0855 g/mol ≈ 0.755 moles
H: 1.16 g / 1.0079 g/mol ≈ 1.152 moles
O: 49.21 g / 16.00 g/mol ≈ 3.076 moles

Step 3: Find the simplest whole-number ratio of the elements to get the empirical formula.

Divide all the moles by the smallest number of moles (0.755 moles):

Mg: 1.152 moles / 0.755 moles ≈ 1.525 ≈ 2 (rounded to the nearest whole number)
Si: 0.755 moles / 0.755 moles = 1
H: 1.152 moles / 0.755 moles ≈ 1.525 ≈ 2 (rounded to the nearest whole number)
O: 3.076 moles / 0.755 moles ≈ 4.07 ≈ 4 (rounded to the nearest whole number)

The empirical formula of chrysotile asbestos is Mg2SiO4H2.

Step 4: Calculate the molecular formula using the molar mass and empirical formula.

To find the molecular formula, we need to compare the molar mass of the empirical formula (Mg2SiO4H2) to the given molar mass of chrysotile (520.8 g/mol).

Molar mass of empirical formula (Mg2SiO4H2):
Mg: 2 × 24.305 g/mol ≈ 48.61 g/mol
Si: 1 × 28.0855 g/mol ≈ 28.09 g/mol
O: 4 × 16.00 g/mol ≈ 64.00 g/mol
H: 2 × 1.0079 g/mol ≈ 2.02 g/mol

Total molar mass: 48.61 g/mol + 28.09 g/mol + 64.00 g/mol + 2.02 g/mol ≈ 142.72 g/mol

Now, we calculate the molecular formula by dividing the molar mass of chrysotile by the total molar mass of the empirical formula:

Molecular formula = 520.8 g/mol / 142.72 g/mol ≈ 3.65

Rounded to the nearest whole number, the molecular formula for chrysotile asbestos is approximately 4 times the empirical formula:

Molecular formula: 4(Mg2SiO4H2) = Mg8Si4O16H8

Therefore, the molecular formula for chrysotile asbestos is Mg8Si4O16H8.