The Student Room Group

Buffer Solutions

Which of the following mixtures, in an aqueous solution, will produce a buffer solution?
I. 50 cm3 of 0.1 mol dm–3 CH3COONa and 50 cm3 of 0.1 mol dm–3 CH3COOH
II. 50 cm3 of 0.1 mol dm–3 NH3 and 50 cm3 of 0.1 mol dm–3 NH4Cl
III. 50 cm3 of 0.1 mol dm–3 NaOH and 50 cm3 of 0.2 mol dm–3 CH3COOH

Why Is (I) considered as a buffer?
Original post by PleaseHelpAsap
Which of the following mixtures, in an aqueous solution, will produce a buffer solution?
I. 50 cm3 of 0.1 mol dm–3 CH3COONa and 50 cm3 of 0.1 mol dm–3 CH3COOH
II. 50 cm3 of 0.1 mol dm–3 NH3 and 50 cm3 of 0.1 mol dm–3 NH4Cl
III. 50 cm3 of 0.1 mol dm–3 NaOH and 50 cm3 of 0.2 mol dm–3 CH3COOH

Why Is (I) considered as a buffer?


a buffer can be made by a weak acid and its conjugate base.
in part (i), the mixture contains the same moles of the methanoic acid and sodium methanoate, which is a conjugate base of methanoic acid (salt) formed from a strong alkali like naoh and a weak acid( methanoic acid).
hope that helps
Original post by Awsomedude
a buffer can be made by a weak acid and its conjugate base.
in part (i), the mixture contains the same moles of the methanoic acid and sodium methanoate, which is a conjugate base of methanoic acid (salt) formed from a strong alkali like naoh and a weak acid( methanoic acid).
hope that helps


Shouldn't the methanoic acid be in excess?

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