The thallium (present as Tl2SO4) in a 9.468 g pesticide sample was precipitated as thallium(I) iodide. Calculate the mass percent of Tl2SO4 in the sample if 0.1370 g of TlI was recovered.
Well, I have to say, chemistry problems always get my electrons buzzing with excitement! Let's tackle this one together.
First, we need to find the moles of TlI that were recovered. To do that, we can use the molar mass of TlI, which is 331.4 g/mol. Dividing 0.1370 g by the molar mass will give us the number of moles of TlI.
0.1370 g / 331.4 g/mol = 0.000414 mol of TlI
Since Tl2SO4 contains two moles of Tl for every one mole of Tl2SO4, we can conclude that the number of moles of Tl2SO4 present in the sample is double that of TlI.
0.000414 mol x 2 = 0.000828 mol of Tl2SO4
Now, we need to find the mass of Tl2SO4 in the sample. We can use the molar mass of Tl2SO4, which is 504.8 g/mol, and multiply it by the number of moles of Tl2SO4.
0.000828 mol x 504.8 g/mol = 0.4172 g of Tl2SO4
Finally, to calculate the mass percent of Tl2SO4 in the sample, we divide the mass of Tl2SO4 by the mass of the entire sample (9.468 g) and multiply by 100.
(0.4172 g / 9.468 g) x 100 = 4.40%
So, the mass percent of Tl2SO4 in the sample is approximately 4.40%. Oh, chemistry, you're such a balancing act!
To find the mass percent of Tl2SO4 in the sample, we need to compare the mass of Tl2SO4 to the total mass of the sample and calculate the percentage.
1. Calculate the molar mass of Tl2SO4 (thallium sulfate).
- The molar mass of thallium (Tl) is 204.38 g/mol.
- The molar mass of sulfur (S) is 32.07 g/mol.
- The molar mass of oxygen (O) is 16.00 g/mol.
- Tl2SO4 consists of 2 thallium atoms, 1 sulfur atom, and 4 oxygen atoms.
- Therefore, the molar mass of Tl2SO4 is:
(2 × 204.38 g/mol) + (32.07 g/mol) + (4 × 16.00 g/mol) = 512.65 g/mol
2. Calculate the moles of Tl2SO4 in the sample.
- Convert the mass of TlI recovered (0.1370 g) to moles using the molar mass of TlI.
- The molar mass of TlI is the molar mass of thallium (204.38 g/mol) + the molar mass of iodine (126.90 g/mol).
- Therefore, the molar mass of TlI is 331.28 g/mol.
- Moles of TlI = Mass of TlI / Molar mass of TlI
= 0.1370 g / 331.28 g/mol
3. Use the stoichiometry of the reaction to find the moles of Tl2SO4.
- From the balanced equation, we can see that for 1 mole of Tl2SO4, 2 moles of TlI are required.
- So, Moles of Tl2SO4 = (Moles of TlI) / 2
4. Calculate the mass of Tl2SO4 in the sample.
- Mass of Tl2SO4 = Moles of Tl2SO4 × Molar mass of Tl2SO4
5. Calculate the mass percent of Tl2SO4 in the sample.
- Mass percent = (Mass of Tl2SO4 / Total mass of the sample) × 100
Now, let's calculate the mass percent of Tl2SO4 in the sample step by step:
1. Molar mass of Tl2SO4 = 512.65 g/mol
2. Moles of TlI = 0.1370 g / 331.28 g/mol = 0.0004136 mol
3. Moles of Tl2SO4 = (0.0004136 mol) / 2 = 0.0002068 mol
4. Mass of Tl2SO4 = (0.0002068 mol) × (512.65 g/mol) = 0.1060 g
5. Mass percent of Tl2SO4 = (0.1060 g / 9.468 g) × 100 = 1.12%
Therefore, the mass percent of Tl2SO4 in the pesticide sample is 1.12%.
To calculate the mass percent of Tl2SO4 in the sample, we need to use the information given in the problem.
1. Determine the molar mass of Tl2SO4:
The molar mass of Tl2SO4 can be calculated by multiplying the atomic mass of each element by the number of atoms in the compound and then summing them up.
Tl: Atomic mass = 204.37 g/mol, Number of atoms = 2
S: Atomic mass = 32.06 g/mol, Number of atoms = 1
O: Atomic mass = 16.00 g/mol, Number of atoms = 4
Molar mass of Tl2SO4 = (204.37 g/mol * 2) + (32.06 g/mol * 1) + (16.00 g/mol * 4)
2. Calculate the moles of TlI recovered:
The moles of TlI can be calculated using its molar mass, which is determined in the same way as step 1 but with Tl and I elements.
Tl: Atomic mass = 204.37 g/mol, Number of atoms = 2
I: Atomic mass = 126.90 g/mol, Number of atoms = 2
Molar mass of TlI = (204.37 g/mol * 2) + (126.90 g/mol * 2)
Moles of TlI = Mass of TlI recovered / Molar mass of TlI
3. Calculate the moles of Tl2SO4:
From the chemical equation, we can see that the molar ratio of Tl2SO4 to TlI is 1:2. This means that for every mole of Tl2SO4, two moles of TlI are produced.
Moles of Tl2SO4 = Moles of TlI / 2
4. Calculate the mass percent:
Mass percent can be calculated by dividing the mass of Tl2SO4 by the total mass of the pesticide sample and then multiplying by 100.
Mass percent = (Moles of Tl2SO4 * Molar mass of Tl2SO4) / Mass of the pesticide sample * 100
Substitute the values obtained from steps 1 to 3 into the formula and calculate the answer.