(A) Phosphorous is a white, waxy solid, normally stored under water because it spontaneously inflames in air.
(B) Sulphuric acid is a viscous liquid that reacts with barium chloride, giving a white ppt of barium sulphate.
BaCl2+H2SO4→BaSO4↓white+2HCl
(C) Nitric acid is an acid that reacts with copper metal, releasing brown fumes.
3Cu+8HNO3(dilute)→3Cu(NO3)2+2NO↑+4H2O
Cu+4HNO3(conc)→Cu(NO3)2+2NO2↑+2H2O
(D) Chlorine is a pale greenish yellow gas that dissolves in aqueous NaOH to give a solution used as a bleach.
Cl2+2NaOH(cold and dilute)→NaCl+NaOCl+H2O
3Cl2+6NaOH(hot and conc)→5NaCl+NaOCl3+3H2O