The number of 2-centre-2-electron and 3-centre -2-electron bonds in B₂H₆, respectively, are :

Haemoglobin and gold sol are examples of :

5.1 g NH₄SH is introduced in 3.0 L evacuated flask at 327ºC. 30% of the solid NH₄SH decomposed to NH₃ and H₂S as gases . The Kp of the reaction at 327^oC is (R = 0.082 L atm mol^–1 K^–1, Molar mass of S = 32 g mol^–1 molar mass of N = 14 g mol^–1)

An aromatic compound 'A' having molecular formula C₇H₆O₂ on treating with aqueous ammonia and heating forms compound 'B'. The compound 'B' on reaction with molecular bromine and potassium hydroxide provides compound 'C' having molecular formula C₆H₇N.. The structure of 'A' is