How much more acetic acid (pKa = 4.76) than acetate should be in solution to maintain a pH of 4.00?

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Help I don’t know what to do.. I keep getting 0.17 which is the wrong answer. How can I solve this?

Alize Kuhn · Accepted Answer

Use the Henderson-Hasselbalch equation to find the needed ratio of Ac-/HAc. pH = pKa + log ([acetate] / [acetic acid])4.00 = 4.76 + log ([acetate] / [acetic acid])-0.76 = log ([acetate] / [acetic acid])10^-0.76 = ([acetate] / [acetic acid]) = 0.174 Inverting that, ([acetic] / [acetate]) = 1 / 0.174 = 5.75

Alize Kuhn · Answer

This Site Might Help You.RE:How much more acetic acid (pKa = 4.76) than acetate should be in solution to maintain a pH of 4.00?Help I don't know what to do.. I keep getting 0.17 which is the wrong answer. How can I solve this?

Alize Kuhn · Answer

For the best answers, search on this site https://shorturl.im/U2vB3Use Henderson-Hasselbalch equation. pH = pKa + log₁₀( [CH₃COO⁻]/[CH₃COOH] ) Since acetic acid is a weak acid, it can be assumed that ionization of the acetic acid and hydrolysis of the acetate ions are negligible. Hence: [CH₃COOH] = 2M and [CH₃COO⁻] = [NaCH₃COO] = (5g / 82g/mol) / 0.01L = 6.1M The pH of this buffer solution is: pH = 4.76 + log₁₀( 6.1 / 2 ) = 5.24

Dr. Reggie Bosco DVM

How much more acetic acid (pKa = 4.76) than acetate should be in solution to maintain a pH of 4.00?

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