Question

A solution contains 410.3 g of H SO per litre of solution at 20° C. If the density is 1.243 g/ml
molality is
(1) 618.4 m
(2) 846 lm
(3)18.64 m
(4) 5.027 m​

Answer 1

Answer:

4) 5.027

Explanation:

Quantity of HSO = 410.3g (Given)

One liter of solution weights = Density = 1243g  (Given)

Temperature = 20° C (Given)

Since, 410.3 g of the solution is HSO then the rest of the weight will be -

= 1243 - 410

= 833 g ( which must be water)  

Molar mass -

H = 2 x 1= 2  

S = 1 x 32=32  

O = 4 x 16= 64

Thus, the molar mass of HSO = 98.078 g/mol  ( 64+32+2)

Moles of HSO = 410.3 g/ 98.078 = 4.183  

Now, m = moles solute / Kg solvent

= 4.183 / 0.833

= 5.027

Thus, the molarity of the solutin is 5.027.