Given data:The concentration of hydrofluoric acid = 0.25 MThe volume of hydrofluoric acid = 250 mLThe pH of the solution is 3.50Mole calculation:We know that,pk = -log K₁The K₁ for hydrofluoric acid is 6.8 x 10-4The moles of hydrofluorie acid that is needed can be calculated using the Henderson-Hasselbalch equationas follows,[conjugate base][weak acid]pH= pk + log.pH= pk + log.3.50= -log K + log;[Buffer, base][Buffer. acid][F](HF)(0.25 M)= -log(6.8 x 10-4) + log- (HF]= 3.167 +log[0.25] -log[HF]log[HF]= 3.167 -0.602 - 3.50-0.9351[HF] = 0.1161 MTherefore, the concentration of hydrofluoric acid is 0.1161 MThe mole of hydrofluoric acid is calculated as follows,Concentration =How didmoleTotal volumemol HF=Concentration x Total volume= 0.1161 x 0.250 L= 0.029 molTherefore, the number of moles required is 0.029 molthey get this?

To reach the result -0.9351 from the above given data and Handerson - Hasselbalch equation for the…

Given data: The concentration of hydrofluoric acid = 0.25 M The volume of hydrofluoric acid = 250 mL The pH of the solution is 3.50 Mole calculation: We know that, pk = -log K₁ The K₂ for hydrofluoric acid is 6.8 x 10-4 The moles of hydrofluorie acid that is needed can be calculated using the Henderson-Hasselbalch equation as follows, pH= pk + log- [conjugate base] [weak acid] [Buffer. base] pH= pk + log- [Buffer. acid] [F] 3.50= -log K + log (HF) = -log(6.8 x 10-¹) + log- = 3.167 +log[0.25] -log[HF] log[HF]= 3.167 -0.602 - 3.50 -0.9351 [HF] = 0.1161 M Therefore, the concentration of hydrofluoric acid is 0.1161 M The mole of hydrofluoric acid is calculated as follows, Concentration=; mole Total volume (0.25 M) [HF] How did mol HF=Concentration x Total volume = 0.1161 x 0.250 L = 0.029 mol Therefore, the number of moles required is 0.029 mol they get this?

Given data: The concentration of hydrofluoric acid = 0.25 M The volume of hydrofluoric acid = 250 mL The pH of the solution is 3.50 Mole calculation: We know that, pk = -log K₁ The K₂ for hydrofluoric acid is 6.8 x 10-4 The moles of hydrofluorie acid that is needed can be calculated using the Henderson-Hasselbalch equation as follows, pH= pk + log- [conjugate base] [weak acid] [Buffer. base] pH= pk + log- [Buffer. acid] [F] 3.50= -log K + log (HF) = -log(6.8 x 10-¹) + log- = 3.167 +log[0.25] -log[HF] log[HF]= 3.167 -0.602 - 3.50 -0.9351 [HF] = 0.1161 M Therefore, the concentration of hydrofluoric acid is 0.1161 M The mole of hydrofluoric acid is calculated as follows, Concentration=; mole Total volume (0.25 M) [HF] How did mol HF=Concentration x Total volume = 0.1161 x 0.250 L = 0.029 mol Therefore, the number of moles required is 0.029 mol they get this?

Principles of Modern Chemistry

8th Edition

ISBN:9781305079113

Author:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler

Publisher:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler

Chapter15: Acid–base Equilibria

Section: Chapter Questions

Problem 103AP

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