215) When ammonia is added to pure water, the concentration of which of the following species already present, will decrease?

216) The equilibrium constant K_p for a homogeneous gaseous reaction is 10⁻⁸. The standard Gibb′s free energy change, ΔG^o for the reaction is:

217) If pH of a saturated solution of Ba(OH)₂ is 12, the value of K_sp is:

218) What amount of Cl₂ gas liberated at anode, if 1 A current is passed for 3 min from NaCl solution?

219) 100 mL HCN of 0.1M is titrated with 100 mL 0.1M NaOH solution. At the neutral point, pH of this solution will be: (pK_a of HCN = 4.74)