You wish to prepare 125 milliliters of 0.0500 M phosphate buffer, pH 7.90, from phosphoric acid [a liquid; specific gravity = 1.69, assay by weight = 85.6%; MW = 97.999] and potassium hydroxide [a solid; purity 86%; MW = 56.11].
You wish to prepare 125 milliliters of 0.0500 M phosphate buffer, pH 7.90, from phosphoric acid [a liquid; specific gravity = 1.69, assay by weight = 85.6%; MW = 97.999] and potassium hydroxide [a solid; purity 86%; MW = 56.11].
Use pKa (not pKa’) from Table 2-1 in the coursepack. (This pKa = 7.2) Me: What is the molar concentration of the phosphoric acid starting material? Me: What volume (in milliliters) of phosphoric acid would you need to make the buffer? Me: What mass (in grams) of KOH would you need to prepare 25.0 mL of 1.00 M KOH? Me: What volume (in milliliters) of the 1.00 M KOH would be needed to adjust the pH to 7.90?
Any tutor that proves to be competent in the field of chemistry will receive a bonus $50. Come on, one of you clowns has to know what you’re doing.
Also up for sale: $1.00 for every message sent to taado calling him a clown. Screenshot for proof, and you’ll be paid via paypal.
Comments
Post a Comment