Question

A compound is found to contain 7.962 % silicon , 20.10 % chlorine , and 71.94 % iodine by mass.

a. The empirical formula for this compound is_______ .
b. The molar mass for this compound is 352.8 g/mol. The molecular formula for this compound is:_____

Answer 1

A. Empirical formula => SiCl₂I₂

B. Molecular formula = SiCl₂I₂

Step-by-step explanation:

From the question given above, the following data were:

Silicone (Si) = 7.962 %

Chlorine (Cl) = 20.10 %

Iodine (I) = 71.94 %

Molar mass of compound = 352.8 g/mol

Empirical formula =?

Molecular formula =?

A. Determination of the empirical formula of the compound.

Si = 7.962 %

Cl = 20.10 %

I = 71.94 %

Divide by their molar mass

Si = 7.962 / 28 = 0.284

Cl = 20.10 / 35.5 = 0.566

I = 71.94 / 127 = 0.566

Divide by the smallest

Si = 0.284 / 0.284 = 1

Cl = 0.566 / 0.284 = 2

I = 0.566 / 0.284 = 2

Empirical formula => SiCl₂I₂

B. Determination of the molecular formula of the compound.

Empirical formula => SiCl₂I₂

Molar mass of compound = 352.8 g/mol

Molecular formula =?

Molecular formula = [SiCl₂I₂]ₙ

[SiCl₂I₂]ₙ = 352.8

[28 + (2×35.5) + (2×127)]n = 352.8

[28 + 71 + 254]n = 352.8

353n = 352.8

Divide both side by 353

n = 352.8 / 353

n = 1

Molecular formula = [SiCl₂I₂]ₙ

Molecular formula = [SiCl₂I₂]₁

Molecular formula = SiCl₂I₂