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)

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 -

Decomposition of X exhibits a rate constant of 0.05 $$\mu $$g/year. How many year are required for the decomposition of 5$$\mu $$g of X into 2.5 $$\mu $$g?