A certain liquid X has a normal boiling point of 128.20°C and a boiling point elevation constant Kb=1.03·°C·kgmol?1. Calculate the boiling point of a solution made of 38.5g of iron(III) chloride (FeCl3) dissolved in 250.g of X.

Be sure your answer is rounded to the correct number of significant digits.

Respuesta :

Answer:

129.18 °C

Explanation:

The elevation in the boiling point is a colligative property that can be calculated using the following expression.

ΔTb = Kb × b

where,

ΔTb: elevation in the boiling point

Kb: boiling point elevation constant

b: molality

The molality of the solution is:

[tex]b=\frac{38.5gFeCl_{3}}{(162.2 g FeCl_{3}/molFeCl_{3}).0.250 kgX} =0.949m[/tex]

ΔTb = Kb × b

ΔTb = (1.03 °C.kg/mol) × (0.949 mol/kg) = 0.977°C

The boiling point of the solution is:

128.20°c + 0.977°C = 129.18 °C