InterviewSolution
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InterviewSolution
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`K_(a)` for butyric acid is `2.0xx10^(-5)`. Calculate pH and hydroxyl ion concentration in `0.2M` aqueous solution of sodium butyate. |
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Answer» (I). Calculation of pH of the solution. sodium butyrate is a salt of strong base and weak acid. `pH =- 1/2 [log K_(w) +logK_(a) - logC]` According to available data , `K_(w) =1.0 xx 10^(-14), K_(a) = 2.0 xx10^(-5) , C= 0.2 M` `pH =- 1/2 [log 10^(-14) + log (2.0xx10^(-5))- log (0.2)]` `=- 1/2 [(-14)- (5 -log2) +0.698] =-1/2 [-14-4 .699+0.698] =9.00` (II). Calculation of hydroly ion concentration. `pH =9 , pOH = pK_(w) -pH =14 -9 =5 :. [OH^(-)] =10^(-5) M` |
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