What volume (in ml) of 0.2 M RNH 3 Cl solution should be added to 100 ml of 0.1 M RNH 2 solution to produce a buffer solution of pH = 8.4 at 2 5 ∘ C ? (Given pK b of RNH 2 = 5 ; lo g 2 = 0.3 )

Question

What volume (in ml) of 0.2 M RNH 3 ​ Cl solution should be added to 100 ml of 0.1 M RNH 2 ​ solution to produce a buffer solution of pH = 8.4 at 2 5 ∘ C ? (Given pK b ​ of RNH 2 ​ = 5 ; lo g 2 = 0.3 )

TestHub · Accepted Answer

​ pO H = p K b ​ + lo g [ RN H 2 ​ RN H 3 + ​ ​ ] ​ ​ ​ ​ ​ ​ 5.6 = 5 + lo g ( 10 x ​ ) 10 x ​ = 4 x = 40 m m o l 40 = 0.2 × V o l u m e V o l u m e = 200 m l .

Chemistry - Ionic Equilibrium Question with Solution | TestHub

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