An organic compound having C, H and S elements contains 4% sulphur. The minimum molecular weight of the compound is

Minimum one S atom must be present in the molecule. That means minimum weight of s is 32.
4% 5$\Rightarrow$If 4 gm of S is present GMW is 100 32gm of S is present GMW is ?
$\frac{32\times 100}{4}=800\mathrm{gm}$
$\therefore$MW = 800