Question

Calculate the mole fraction of Mg I 2 in an aqueous solution prepared by dissolving 0.400 moles of Mg I 2 in 850.0 g of water. Calculate the mole fraction of Mg I 2 in an aqueous solution prepared by dissolving 0.400 moles of Mg I 2 in 850.0 g of water.

Answer 1

The molar fraction (X) of a solution of 0.4mol of MgI2 in 850g of water is 0.008

We calculate the moles of water with the molecular weight (MW):

moles = mass / MW = 850g / 18g / mol = 47.22 mol

The molar fraction is calculated:

Xi = ni / nt

where :

Xi: molar fraction of compound i

ni: moles of compound i

nt: total moles in the solution

nt = nagua + nMgI2 = 47.22 mol + 0.4 mol = 47.62 mol

X (MgI2) = 0.4 mol / 47.62 mol = 0.008

La fracción molar (X) de una solución de 0,4mol de MgI2 en 850g de agua, es de 0,008

Calculamos los moles de agua con el peso molecular:

moles = masa / PM = 850g / 18g/mol = 47,22 mol

la fraccion molar se calcula:

Xi = ni/ nt

donde :

Xi : fraccion molar del compuesto i

ni : moles del compuesto i

nt : moles totales en la solucion

nt = nagua + nMgI2 = 47,22 mol + 0,4 mol = 47,62 mol

X(MgI2) = 0,4 mol / 47,62 mol = 0,008