Question

aqua solution of H2 s o4 has concentration 18% weight by weight and 22.5% weight by volume find out density of solution

Answer 1

concentration of H2SO4 = 18% weight by weight .

means, 100g of solution contains 18 g of H2SO4.

no of mole of solute(H2SO4) = weight of H2SO4/molar weight of H2SO4

= 18/98 = 9/49 mol

mass of solvent = 100 - 18 = 82g

no molality of solution = no of mole of solute/mass of solvent in kg

= (9/49)/(82/1000)

= 9 × 1000/(82 × 49)

≈ 2.24 m

again, concentration of H2SO4 = 22.5 weight by volume .

means, 100ml of solution contains 22.5g of H2SO4.

no of mole of H2SO4 = 22.5/98

volume of solution = 100ml

so, molarity = no of mole of solute/volume of solution in L

= (22.5/98)/(100/1000)

= 225/98 ≈ 2.295M

we know,

1/m = d/M - Ms/1000

where m is molality, M is molarity and Ms is mass of solute (H2SO4)

then, 1/2.24 = d/2.295 - 98/1000

or, 1/2.24 - 0.098 = d/2.295

or, 0.4464 - 0.098 = d/2.295

or, d = 0.799 ≈ 0.8 g/ml

hence, density of solution is 0.8 g/ml