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The pH at which Mg(OH)2 [ Ksp = 1 10-11 ] begins to precipitate from a solution containing 0.10 M Mg2+ ions is .
9
Precipitation starts when [Mg2+][OH-]2 = Ksp
0.10 [OH-]2 = 1 10-11 ⇒ [OH-]2 = 10-10
⇒ [OH-] = 10-5 M ⇒ pOH = 5
∴ pH = 14 − 5 = 9
Answer: 9
The pH of an aqueous solution containing 1 M benzoic acid (pKa = 4.20) and 1 M sodium benzoate is 4.5. The volume of benzoic acid solution in 300 mL of this buffer solution is mL. (given : log 2 = 0.3)
For the reaction N2O4(g) 2NO2(g), Kp = 0.492 atm at 300 K. Kc for the reaction at same temperature is 10-2. (Given : R = 0.082 L atm mol-1 K-1)
The following concentrations were observed at 500 K for the formation of NH3 from N2 and H2. At equilibrium ; [N2] = 2 10-2 M, [H2] = 3 10-2 M and [NH3] = 1.5 10-2 M. Equilibrium constant for the reaction is .
Given below are two statements : In the light of the above statements, choose the most appropriate answer from the options given below :