The hardness of a water sample (in terms of equivalents of CaCO₃) containing 10^–3 M CaSO₄ is (Molar mass of CaSO₄ = 136 g mol^–1)

A metal on combustion in excess air forms X. X upon hydrolysis with water yields H₂O₂ and O₂ along with another product. The metal is :

Poly $$\beta $$ –hydroxybutyrate-co-$$\beta $$-hydroxyvalerate (PHBV) is a copolymer of

The metal d-orbitals that are directly facing the ligands in K₃[Co(CN)₆] are -