Question

Why sulphuric acid is oily and viscous liquid?

Answer 1

The crystals of green vitriol $(FeS{O}_4.7H_{2}O)$ are heated and distilled to give sulfuric acid which is in the form of an oily viscous liquid.

The molecules of $H_{2}S{O}_4$ are larger than that of $H_{2}O$ since the Vander Waal's forces are higher in $H_{2}S{O}_4$. Thus the particles are forced to move through a small volumetric area with a stress acting on it. Therefore, it is a more viscous fluid than water.

Hence sulphuric acid is oily and viscous liquid.