ढलवा दीवारों ( concept of battered wall ) की अवधारणा द्वारा पेश की गई थी।
The correct statement with regard to H+2 & H−2 is
Assertion : For drying H2S, Conc. H2SO4 cannot be used.
Reason: Moist H2S is oxidized by Conc.H2SO4