Respuesta :

Edufirst

Answer:

       [tex]\large\boxed{\large\boxed{0.091}}[/tex]

Explanation:

The mole fraction of a component in a mixture is the number of moles of the component divided by the total number of moles of all the components, multiplied by 100.

The symbol X is used to represent the mole fraction.

            [tex]X_A=\dfrac{\text{number of moles of component A}}{\text{number of moles of all the components}}\times 100[/tex]

1. Convert masses in grams to number of moles

Formula:

  • number of moles = mass in grams / molar mass

a) Lithium bromide

  • Chemical Formula: LiBr
  • Molar mass: 86.845 g/mol

       [tex]\text{Number of moles}=\dfrac{174g}{86.845g/mol}=2.00mol[/tex]

b) Water

  • Chemical formula: H₂O
  • Molar mass: 18.015 g/mol

      [tex]\text{Number of moles}=\dfrac{360g}{18.015g/mol}=19.98mol\approx 20.0mol[/tex]

c) Total number of moles = 2.00 mol + 20.0 mol = 22.0 mol

2. Mole fraction of lithium bromide

           [tex]\text{Mole fraction of lithium bromide}=\dfrac{2.00}{22.0}=0.091[/tex]

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