If the complete conversion of 1.383g of XI2 results in the formation of 0.564g of XCl2, what is the atomic mass of the element X

So X has an atomic mass of 55.05 u, and is probably Mn

Explanation:

Step1: Balance the equation

XI2 + Cl2 → XCl2 + I2

Step2: find the molar mass of the compounds

Compounds:

X ⇒ Molar mass = M

XI2 ⇒ Molar mass = M + 2*126.9 u

XCl2 ⇒Molar mass = M + 2*35.45u

⇒For 1 mole XI2 we have 1 mole Cl2 reacting, as well as 1 mole XCl2 and 1 mole I2 produced.

Step 3: Calculating the atomic mass

(1.383g * XI2) / (M + 2*126.90 u) = (0.564g * XCl2) / (M + 2 * 35.45u)

1.383 (M + 2 * 35.45 u) = 0.564 (M + 2*126.90)

1.383M + 98.0547 = 0.564 M + 143.1432

1.383 M - 0.564 M = 143.1432 - 98.0547

0.819 M = 45.0885

M = 55.05 u

So X has an atomic mass of 55.05 u ⇒ if we look at the periodic table we can find that the closest element is Manganese (Mn)

MnI2 + Cl2 → MnCl2 + I2