Answer:
density is 1.057 g/mL
mole fraction is 0.0180
molarity is 0.98 mol/L
mole fraction is 0.0180
Explanation:
Given data
acid mass = 10 g
water volume = 100 mL
total volume = 104 mL
density = 1 g/cm³
to find out
the density, mole fraction, molarity, and molality
solution
first we calculate the density that is = total mass g / volume of solution mL
total mass = mass of H3PO4 + water mass
so water mass = density x volume
water mass = 100 ml x 1.0 g/cm3
water mass = 100 g
so total mass = 110.00 g
so that
density = total mass g / volume of solution mL
density = 110 / 104 = 1.057 g/mL
now we calculate no of moles in solvent i.e = mass H2O / mlar mass H2O
no of moles in solvent = 100/18.015 = 5.55 moles
and no of moles in solute i.e = mass of H3PO4 / mlar mass in H3PO4
moles in solute i.e = 10/ 97.994 = 0.102 moles
so total moles is 5.55 + 0.102 = 5.652 moes
so now mole fraction = no of moles in solute / total moes
mole fraction = 5.55 / 5.65
mole fraction is 0.0180
now we calculate first
mole fraction in solute and solvent that is
mole fraction in solute = no of moles in solute/ total moles
mole fraction in solute = 0.102 /5.65
mole fraction in solute is 0.0180
and mole fraction in solvent that = no of moles in solvent/ total moles
mole fraction in solvent that = 5.55/ 5.65
mole fraction in solvent that is 0.982
so molarity = no of moles of solute / volume
molarity = 0.102/0.104
molarity is 0.98 mol/L
and molality is = no of moles of solute / mass
molality = 0.102 / 100
molality is 1.02 mol/kg
