Question

Barium can be analyzed by precipitating it as BaSO₄ and weighing the precipitate. When a 0.369g sample of a barium compound was treated with excess H₂SO₄, 0.153g of BaSO₄ formed. What is the percentage of barium in the compound?

Answer 1

To find the percentage of barium in the compound, we calculate the mass of barium in the BaSO₄ precipitate and divide it by the total mass of the compound, then multiply by 100. In this case, the percentage of barium in the compound is 24.36%.

Step-by-step explanation:

To calculate the percentage of barium in the compound, we need to determine the mass of barium in the compound and divide it by the total mass of the compound, then multiply by 100.

First, we need to determine the mass of barium (Ba) in the BaSO₄ precipitate. From the given information, the mass of BaSO₄ formed is 0.153g. The molar mass of BaSO₄ is 233.43 g/mol, so we can calculate the moles of BaSO₄:

Moles of BaSO₄ = mass of BaSO₄ / molar mass of BaSO₄

Moles of BaSO₄ = 0.153g / 233.43 g/mol = 0.00065519 mol

Since the ratio of Ba to BaSO₄ is 1:1, the moles of barium (Ba) in the compound is also 0.00065519 mol. Now we can calculate the mass of barium:

Mass of Ba = moles of Ba x molar mass of Ba = 0.00065519 mol x 137.33 g/mol = 0.0899 g

Finally, we can calculate the percentage of barium in the compound:

Percentage of barium = (mass of Ba / mass of compound) x 100 = (0.0899 g / 0.369 g) x 100 = 24.36%