How many millilitres of conc. H₂SO₄ of specific gravity 1.84 containing 98% H₂SO₄ by weight are required to prepare 200 ml of 0.5N solution. Please explain also.

molecular weight of sulfuric acid = 98g
Specific Gravity  = 1.84
% of pure sulphuric acid/gm = 98%
number of replacable hydrogens = 2
Gram Equivalent Weight =molecular weight/replaceable hydrogens
98/2 = 49g

Required substance weight = eq. wt. x Normality x Volume (in L)
=49gm x0.5N X 0.2 Litres = 4.9 g 

Dilution Factor = Specific Gravity x concentration of pure acid.
=1.84 x 0.98 = 1.8gm
 

Volume required = mass required/dilution factor 
4.9/1.8 = 2.72ml.