Question

The thallium (present as Tl2SO4) in a 9.486-g pesticide sample was precipitated as thallium(I) iodide. Calculate the mass percent of Tl2SO4 in the sample if 0.1824 g of TlI was recovered.

Answer 1

To calculate the mass percent of Tl2SO4 in the sample, find the molar mass of Tl2SO4 and divide it by the total mass of the sample, then multiply by 100. The mass percent is 1.924%.

Step-by-step explanation:

To calculate the mass percent of Tl2SO4 in the sample, we need to find the mass of Tl2SO4 and divide it by the total mass of the sample, then multiply by 100.

First, we need to find the molar mass of Tl2SO4:

Thallium (Tl) has a molar mass of 204.38 g/mol, and sulfur (S) has a molar mass of 32.07 g/mol.

Oxygen (O) has a molar mass of 16.00 g/mol.

So, the molar mass of Tl2SO4 is:

(2 * 204.38 g/mol) + 32.07 g/mol + (4 * 16.00 g/mol) = 504.83 g/mol

Now, we can calculate the mass percent:

Mass percent = (mass of Tl2SO4 / mass of sample) * 100

Mass of Tl2SO4 = mass of TlI recovered

Mass percent = (0.1824 g / 9.486 g) * 100 = 1.924%