An element X has a triiodide with the empirical formula XI3 and a trichloride with the empirical formula XCl3. The triiodide is converted to the trichloride according to the equation XI3 Cl2XCl3 I2 If the complete conversion of 1.196 g of XI3 results in the formation of 0.436 g of XCl3, what is the atomic mass of the element X

51.03g/mol is the molar mass of X

Explanation:

Based on the reaction:

2XI₃ + 3Cl₂X → 2XCl₃ + 3I₂

Where 2 moles of XI₃ reacts to produce 2 moles of XCl₃ -The ratio of reaction is 1:1-

To solve this question we must find the mass of X per mole (This is the atomic mass of X).

As the moles of both compounds are the same:

1.196g / 0.436g = Molar mass XI₃ / molar mass XCl₃ (1)

Also:

Molar mass XI₃ = Molar mass X + 380.71g/mol

Molar mass XCl₃ = Molar mass X + 106.36g/mol

Replacing in (1):

2.7431 = (Molar mass X + 380.71g/mol) / (Molar mass X + 106.36g/mol)

2.7431 Molar mass X + 291.76g/mol = Molar mass X + 380.71g/mol

1.7431 Molar mass X = 88.95g/mol

Molar mass X = 51.03g/mol