InterviewSolution
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InterviewSolution
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How much volume of 0.1 M Hac should be added to 50 mL of 0.2 M NaAc solution if we want to prepare a buffer solution of pH 4.91. Given `pK_(a)` for acetic acid is 4.76. |
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Answer» Correct Answer - 70.92 mL `pH=pK_(a) + log. (["Salt"])/(["Acid"]), i.e., 4.91 = 4.76 + log . (["Salt"])/(["Acid"])` or `log. (["Salt"])/(["Acid"])=0.15 or (["Salt"])/(["Acid"])=Antilog 0.15 = 1.41` `("Moles of Salt")/("Moles of Acid")=1.41," i.e.," ((0.2)/(1000)xx50)/((0.1)/(1000)xxV)=1.41 or (0.01)/(1000V)=1.41 or V= 100//1.41 = 70.92 mL` |
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