Question

What is molality of a 1L solution of h2so4 which is 46% wt/vol?..pls ans fst..

Answer 1

46% weight/volume means, that each 100ml of solution or volume of H2SO4 solution will have 46 gm of H2SO4 .

Thus, no. of moles of H2SO4 in 100 ml of solution = 46/98 (molar mass of H2SO4 )= 0.4moles

Now, weight of 100 ml of solution = 100 x 1.40 (density) =140 gm

So, 140 gm of solution contains 46 gm of solute and (140 -46 =)94 gm of solvent.

So, in kg 94 gm of solvent = 0.095 Kg of solvent

Thus, molality of solution = moles of solute/mass of solvent in kg = 0.4/ 0.095 = 4.21

Hope it's Helpful for you.....