Question

11. 2 m aqueous solution of H,SO, contains
[NCERT Pg. 39]
(1) 49 g of H2SO4 per 250 g of solution
(2) 98 g of H_SO, per 250 g of solvent
(3) 49 g of H SO, per 250 g of solvent
(4) 98 g of H2SO4 per 250 g of solution​

Answer 1

Answer:

volume, v=250ml=0.25lit

mass = 49gm

mass of H2SO4= 98gm

no. of moles = given mass /molar mass= 49/98=0.5

Now, M= no. of moles/volume= 0.5/0.25= 2M

hence, option A is correct.

Answer 2

2 m of H2SO4 means:

• 'm' means molality

• 2 moles of sulphuric acid dissolved in 1000 g (or 1 kg) of solvent (i.e. water).

In other words, we can say :

• 2 moles or 98×2 = 196 grams of sulphuric acid in 1 kg solvent.

• or it could also be : 98 grams in 250 grams of solvent.

• This is because 98 grams is ½ moles and 250 grams = ¼ kg. So, net molality also comes as 2m.

$\star$ OPTION 2) IS CORRECT ✔️