AP chem - Beula does not have a buffer solution, since her...

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1. (a) A buffer solution resists changes in pH upon the addition of an acid or base. Preparation: • Mix a weak acid + a salt of a weak acid. • Or mix a weak base + a salt of a weak base. • Or mix a weak acid with about half as many moles of strong base. • Or mix a weak base with about half as many moles of strong acid. • Or mix a weak acid and a weak base. (b) Carla has the correct procedure. She has mixed a weak base, NH3, with the salt of a weak base, NH4Cl. Archie has buffer solution but it has a pH around 5.
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Unformatted text preview: Beula does not have a buffer solution, since her solution consists of a strong acid and a salt of a weak base. Dexter does not have a buffer solution, since his solution consists of a weak base plus a strong base. (c) 1.5 : 1.0 ratio pKa = 7.21 pH = pKa + [HPO 4 2-]/[H 2 PO 4-] 7.40 = 7.21 + [HPO 4 2-]/[H 2 PO 4-] [HPO 4 2-]/[H 2 PO 4-] = 1.5 : 1.0 2. (a) HNO 3 + NaOH H 2 O + NaNO 3 pH = PKa + base/acid pH = 3.35 + 0.450 / 0.300 pH = 4.85 (b) moles...
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This note was uploaded on 12/03/2011 for the course CHEM BIO P 101 taught by Professor Kk during the Spring '11 term at Rochester.

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