Answer:
a) 5.9846 mol/kg
b) 5.018 mol/L
c)0.09725
Explanation:
consider 100 g of solution
now
since the salt is 35 % , water will be 65 %
now
mass of salt = 35 g
mass of water = 65 g
we know that
moles = mass / molar mass
so
moles of salt = 35 g / 90 (g/mol) = 0.389 mol
moles of water = 65 / 18 = 3.6111 mol
now
volume of solution = mass of solution / density of solution
volume of solution = 100 g / ( 1.29 g/ml)
volume of solution = 77.52 ml
volume of solution = 0.07752 L
a)molality = moles of salt / mass of water (kg)
molality = 0.389 mol / 0.065 kg
molality = 5.9846 mol/kg
b)
molarity = moles of salt / volume of solution (L)
molarity = 0.389 mol / 0.07752 L
molarity = 5.018 mol/L
c)
now
total moles in the solution = moles of salt + moles of water
total moles in the solution = 0.389 + 3.6111
total moles in the solution = 4 mol
now
mole fraction of salt = moles of salt / total moles
mole fraction of salt = 0.389 mol / 4 mol
mole fraction of salt = 0.09725
